Nuclear Physics News International

Volume 27, Issue 4 October–December 2017

FEATURING: MIT Bates • Nuclear Symmetry Energy • Nuclear Physics at γELBE

10619127(2017)27(4)

Read Every Issue

Laboratory Portraits

Facilities and Methods

Meeting Reports

Ne w s and Views

Upcoming Events

Nuclear Physics News Volume 27/No. 4

Nuclear Physics News is published on behalf of the Nuclear Physics European Collaboration Committee (NuPECC), an Expert Committee of the European Science Foundation, with colleagues from Europe, America, and Asia.

Editor: Gabriele-Elisabeth Körner Editorial Board Maria José Garcia Borge, Madrid (Chair) Eugenio Nappi, Bari Rick Casten, Yale Klaus Peters, Darmstadt Jens Dilling, Vancouver Hermann Rothard, Caen Rolf-Dietmar Herzberg, Liverpool Hideyuki Sakai, Tokyo Yu-Gang Ma, Shanghai Calin Ur, Bucharest Richard Milner, MIT

Editorial Ofﬁ ce: Physikdepartment, E12, Technische Universitat München, 85748 Garching, Germany, Tel: +49 89 2891 2293, +49 172 89 15011, Fax: +49 89 2891 2298, E-mail: [email protected]

Correspondents (from countries not covered by the Editorial Board and NuPECC) Argentina: O. Civitaresse, La Plata; Australia: A. W. Thomas, Adelaide; Brasil: M. Hussein, São Paulo; India: D. K. Avasthi, New Delhi; Israel: N. Auerbach, Tel Aviv; Mexico: E. Padilla-Rodal, Mexico DF; Russia: Yu. Novikov, St. Petersburg; Serbia: S. Jokic, Belgrade; South Africa: S. Mullins, Cape Town.

Nuclear Physics News ISSN 1061-9127

Advertising Manager Subscriptions Maureen M. Williams Nuclear Physics News is supplied free of charge to PO Box 449 nuclear physicists from contributing countries upon Point Pleasant, PA 18950, USA request. In addition, the following subscriptions Tel: +1 623 544 1698 are available: E-mail: [email protected] Volume 27 (2017), 4 issues Circulation and Subscriptions Personal: $146 USD, £88 GBP, €120 Euro Taylor & Francis Group, LLC Institution: $1,223 USD, £737 GBP, €975 Euro 530 Walnut Street Suite 850 Philadelphia, PA 19106, USA Tel: +1 215 625 8900 Fax: +1 215 207 0050

Copyright © 2017 Taylor & Francis Group, LLC. Reproduction without permission is prohibited. All rights reserved. The opinions expressed in NPN are not necessarily those of the editors or publishers. The views expressed here do not represent the views and policies of NuPECC except where explicitly identiﬁ ed.

Vol. 27, No. 4, 2017, Nuclear Physics News 1 Nuclear Physics Volume 27/No. 4 News

Contents Editorial The Global Nuclear Physics Community by Richard G. Milner...... 3 Laboratory Portrait The MIT Bates Laboratory by Robert Redwine...... 4 Feature Articles Nuclear Symmetry Energy Extracted from Laboratory Experiments by Bao-An Li...... 7 Ion and Neutron Beams Discover New Facts from History by A. Macková, J. Kučera, J. Kameník, V. Havránek, and K. Kranda...... 12 Facilities and Methods The Institute for Nuclear and Radiation Physics at the University of Leuven by Thomas Elias Cocolios, Mark Huyse, and André Vantomme...... 18 Nuclear-Physics Experiments at the Bremsstrahlung Facility γELBE by Ronald Schwengner and Andreas Wagner...... 23 Meeting Reports The International Conference on Isospin, Structure, Reactions, and Energy of Symmetry: Istros 2017 by Martin Veselsky and Martin Venhart...... 27 NPA8: The 8th Nuclear Physics in Astrophysics International Conference by C. Spitaleri, M. Lattuada, and M. La Cognata...... 29 Strangeness in Quark Matter by André Mischke ...... 31 News and Views On the Development of Nuclear Physics in Cuba by Fidel Castro Díaz-Balart...... 33 In Memoriam In Memoriam: Arthur Kerman (1929–2017) by Ernest J. Moniz...... 38 In Memoriam: Peter Paul (1933–2017) by Peter Braun-Munzinger, Volker Metag, and Johanna Stachel...... 39 In Memoriam: Adriaan van der Woude (1930–2017) by Sytze Brandenburg, Muhsin N. Harakeh, and Rolf H. Siemssen...... 40 Calendar...... Inside back cover

Cover Illustration: The toroidal magnet for the Qweak experiment undergoing testing at the Bates Laboratory at MIT. The magnet and support frame were designed and tested at the Bates Laboratory before being shipped to Jefferson Laboratory in Virginia. See the article starting on page ??.

Update 2 Nuclear Physics News, Vol. 27, No. 4, 2017 editorial

The Global Nuclear Physics Community

Scientific inquiry has been a global physics facilities under construction cessful model for large-scale interna- human activity since the dawn of and in planning worldwide. Nuclear tional scientific collaboration. history. We scientists are citizens of physics research is truly an interna- It is essential that our international specific nations and typically receive tional endeavor with a bright future. nuclear physics community redouble funding in support of our research Nuclear physics is especially rel- its efforts to maintain the free flow from the taxes paid by the citizens of evant to confronting some of the most of people and ideas. We must seek to our home country. However, scientific pressing issues facing humanity. Nu- enhance our prominent and successful research is conducted as an interna- clear weapons control, carbon-free en- international scientific meetings. We tional endeavor where the expectation ergy production on a large scale, coun- should take particular care to strive is that nationalism is irrelevant and terterrorism, and nuclear medicine are that nobody is excluded because of that free flow of people and ideas is all areas where nuclear physicists are visa restrictions. Further, enhancing facilitated between the continents and playing a leadership role. Our interna- the careers of our young nuclear phys- across the oceans. tional community provides the frame- ics colleagues worldwide must be a Recently, democratic elections in work where free exchange of ideas high priority, as they constitute the fu- the United Kingdom and the United concerning these politically sensitive ture of our field. When opportunities States have given expression to sig- subjects can take place. Further, nu- arise to participate in outreach to so- nificant anti-immigrant sentiment in clear physicists serve in governments ciety, we should not hesitate to accept these countries, which have long pro- worldwide in leadership positions that them. Continuing to work as a potent vided world leadership in scientific address these critical issues. and coherent international community research and education. Xenophobia The international scientific com- confronting important and fundamen- is also to be found in other countries. munity facilitates free movement of tal scientific questions and engaged The rise of isolationism confronts people. Many of us are immigrants— with unique expertise in addressing “the modern interconnected world in born on one continent and following critical issues facing humanity, nu- which goods, people and ideas have our professional careers on another. clear physicists around the world con- contempt for borders” [1]. Here, I The United States has been particu- stitute an important bulwark against argue that the global nuclear phys- larly generous since the mid-20th cen- isolationism. ics community has played and will tury in welcoming talented foreigners continue to play a significant role in from around the world to a free third- Reference countering isolationism and in main- level education at some of the best re- 1. E. Robinson, The Washington Post, taining the free flow of people and search universities in the world. This July 6, 2017. ideas around the world. wise approach has brought great ben- In 2017, nuclear physics is an intel- efit to the United States. For example, lectually vibrant field with direct and of the approx. 100 U.S. Physics Nobel important applications to society. Ex- Prize winners, 30% were born outside perimental research is conducted at all the United States. In Europe, the Eu- scales from table-top experimentation ropean Union has created an excellent involving a handful of physicists to the network system of funding science Large Hadron Collider with thousands that promotes transnational collabora- of physicists taking part from coun- tion and again has benefited the citi- tries spread across the globe. Theoreti- zens and economies of the countries Richard G. Milner cal nuclear physicists use the world’s in the European Union. Of course, Laboratory for Nuclear Science, MIT, most powerful computers to carry out Europe has also created CERN, the Cambridge, Massachusetts, USA state-of-the art sophisticated calcula- world’s leading high-energy physics tions. There are major new nuclear laboratory and a much-admired, suc-

The views expressed here do not represent the views and policies of NuPECC except where explicitly identified.

Vol. 27, No. 4, 2017, Nuclear Physics News 3 laboratory portrait

The MIT Bates Laboratory

2 0 The Bates Laboratory, operated by unique research-related and radiation- mixing angle sin qW from the Z pole the Massachusetts Institute of Tech- shielded space, and most importantly, down to low energies. nology (MIT), is a valuable techno- a highly trained staff accustomed to The Bates Laboratory was respon- logical and computing resource for the supporting experimental efforts in nu- sible for the design, procurement, international nuclear physics commu- clear and particle physics. The Bates assembly, and testing of the toroidal nity and beyond. The laboratory was staff has expertise in accelerator phys- magnet (QTOR) and support frame originally authorized for construction ics, magnet design, cryogenics, digital used for the Qweak experiment (see in 1967 and began experiments us- and analog electronics, and polarized the figure on the cover of this is- ing high-current beams of electrons in external and internal targets. The tech- sue). Bates also designed, procured, 1974. It underwent several important nical staff consists of a combination of and tested the power supply (9000A, upgrades (to detectors and to the beam scientists, engineers, and technicians. 200V) for the toroid. The toroid was energy, time structure, and polariza- Since 2005 the Bates Laboratory at field mapped at the Bates Laboratory, tion) before completing its mission as MIT has supported a variety of proj- then disassembled and transported a major international accelerator user ects in nuclear and particle physics. to Jefferson Laboratory for the ex- facility in 2005. See, for example, the Typically the Bates staff gets involved periment. A Compton polarimeter to article authored by Richard Milner in in the early stages of project planning, measure the polarization of the elec- Nuclear Physics News in 1999 [1]. Re- when technical choices are still be- tron beam was also designed and con- search directions that were pioneered ing made, and when testing and pro- structed at Bates and delivered to Jef- at Bates include very high-resolution totyping are beginning. As a project ferson Laboratory for this experiment. electron-nucleus scattering using En- matures it is often the case that major The Qweak collaboration recently ergy Loss Spectrometry, and the use of pieces of equipment are designed and released results from the analysis of parity-violating electron scattering to constructed at the Bates Laboratory, the complete data set acquired, and the study important problems in nuclear using the specialized equipment and precision achieved matches the design physics and in Beyond-the-Standard- space at the laboratory. Delivery of the precision. Model tests. equipment to the location of the exper- The Bates Laboratory is located in iment follows final testing at Bates. Design, Construction, and Testing Middleton, Massachusetts, which is The following sections are exam- of the Intermediate Silicon Tracker about 35 km north of the main MIT ples of the projects that the Bates Lab- for the STAR Experiment at the campus in Cambridge. When the labo- oratory has provided major support to. Relativistic Heavy Ion Collider at ratory was established it was clear that Brookhaven National Laboratory there would not be enough space for Design and Construction of the (New York, USA) such a linear-accelerator-based facil- Toroidal Spectrometer Magnet for The Solenoidal Tracker at RHIC ity in the urban environment of Cam- the Qweak Experiment at Jefferson (STAR) collaboration recently up- bridge. However, it was also realized Laboratory (Virginia, USA) graded their tracking capabilities that it was very important that close The Qweak experiment was per- with installation of the Heavy Flavor connections be maintained between formed to provide a precision mea- Tracker, which included a new Inter- the Bates Laboratory and the main surement of parity-violating electron mediate Silicon Tracker (IST). The campus. That in fact has been the case, scattering on the proton at very low goal of the STAR collaboration at and continues to this day. Q2 and forward angles to challenge RHIC is to investigate fundamental When the Bates Laboratory com- predictions of the Standard Model and properties of the new state of strongly pleted its mission as a user facility to search for new physics. This experi- interacting matter produced in rela- in 2005, it was decided by MIT and ment was designed to carry out the first tivistic heavy ion collisions, and to by the U.S. Department of Energy precision measurement of the proton’s provide fundamental studies of the P 2 (DOE) to maintain important techni- weak charge, Q W = 1 – 4sin qW. The nucleon spin structure and dynamics cal capabilities at Bates for the use Standard Model of electro-weak in- in high-energy polarized proton–pro- of researchers in nuclear physics and teractions makes a firm prediction for ton collisions. A critical factor in ac- P other fields. These capabilities include Q W, based on the running of the weak complishing this goal is the ability to

4 Nuclear Physics News, Vol. 27, No. 4, 2017 laboratory portrait

Dupont-engineered cooling medium. to determine if this general approach The IST was installed in STAR at will produce the required intensities of RHIC in 2013 and provided excellent polarized electrons. tracking data for several years. The IST is shown in Figure 1 before instal- Testing and Optimization of an lation. Figure 1. The intermediate silicon Atomic Beam Source of Polarized tracker prior to installation in STAR 3He for use in an Experiment to at RHIC. Design, Construction, and Search for a Non-Zero Value of Optimization of a High-Intensity the Electric Dipole Moment of the directly reconstruct charm and beauty Polarized Electron Source for use Neutron decays as well as flavor-tagged jets in a Future Electron-Ion Collider The search for a non-zero value of to allow a precise measurement of The next-generation major accel- the neutron electric dipole moment is the spectra, yields, and flow of open erator for nuclear physics research in one of the most high-profile experi- charm and beauty production. The re- the United States has been defined ments in physics today. If the neutron construction of open charm and beauty by the community to be an Electron- does have a measureable electric di- production in proton–proton colli- Ion Collider. It is notable that Bates pole moment, it would be a direct indi- sions and for low-multiplicity events played a leadership role in the first cation of physics beyond the Standard in relativistic heavy-ion collisions in accelerator design for an Electron-Ion Model. Almost all extensions to the particular required a new intermediate Collider, a ring-ring concept using the Standard Model predict a value of the tracking system together with the ex- RHIC complex [2]. For some designs nEDM only one to two orders of mag- isting STAR silicon-strip detector and of an Electron-Ion Collider, the phys- nitude below the current experimental the STAR time projection chamber. ics program will depend significantly upper limit. Current efforts to improve The Intermediate Silicon Tracker on the availability of high-intensity the limit are using so-called “co-mag- replaced the STAR Silicon Vertex (on the order of 50 mA average) polar- netometers” to eliminate the effects Tracker, which was based on silicon ized electron beams. Current polarized of non-uniformities in the small mag- drift detectors. The IST was designed, electron sources have achieved aver- netic field in which the polarized neu- constructed, and tested at the Bates age currents of only about 1 mA. So trons precess. An experiment planned Laboratory. Bates staff worked closely a very significant increase in intensity for the Spallation Neutron Source at with Brookhaven National Labora- is needed. tory and Lawrence Berkeley National A team at the Bates Laboratory Laboratory (California, USA) staff to has for several years been pursuing a produce 24 kapton hybrid staves on project to demonstrate a high-inten- carbon fiber supports. Bates was also sity polarized electron source (Figure responsible for fabricating the cooling 2). The basic idea is that a polarized system for the detectors, which used a beam from a laser produces polarized photo-electrons when it strikes a GaAs crystal. Three main features are implemented to achieve very high intensity: the cathode is actively cooled to avoid its overheating by the intense laser beam; the cathode active area is very large to reduce ion bombardment effects; and, since the ion bombardment mostly affects the central area of the cathode, the laser beam is ring shaped, leaving the most vulnerable central area of the cathode unused. Figure 2. The high-intensity polarized Significant progress has been made Figure 3. The atomic beam source of electron source under development at in implementing these features, and polarized 3He under assessment at the the Bates Laboratory. we expect that we will soon be able Bates Laboratory.

Vol. 27, No. 4, 2017, Nuclear Physics News 5 laboratory portrait

Oak Ridge National Laboratory (Ten- ern computing facilities. In addition, a nessee, USA) will use polarized 3He high-speed (10 Gb/s, since upgraded as its “co-magnetometer”. to 100 Gb/s) link to the main MIT At the Bates Laboratory, a team is campus was implemented, which ef- assessing the suitability of an Atomic fectively provides a high-speed link to Beam Source (ABS) of polarized 3He many sites worldwide. Currently the that was originally constructed at Los facility has 71 racks for processors. Alamos National Laboratory (New Each of these racks can provide up to Mexico, USA). A picture of this appa- Figure 4. A computer automated de- 10 kW of power for computing and ratus is shown in Figure 3. The most sign (CAD) of the planned GlueX cooling. The Bates site itself has about crucial assessment concerns the fl ux DIRC with optical boxes. 10 MW of electrical capacity. The and divergence of polarized 3He that High-Performance Computing Facil- the ABS produces. The team will also ity is evolving in its usage, including convert the ABS so that it produces a will transport light from the bar boxes being part of widely shared computing vertical beam, not a horizontal beam. to the photon detector plane. This light resources. This is necessary for it to be of use in will then be utilized to image the Che- The Bates Laboratory at MIT is a the Oak Ridge experiment. We expect renkov radiation emitted from the bar rather unique capability for the nu- that this project will be complete in boxes. Figure 4 shows the design of clear physics community, in that it is roughly a year. the DIRC with the optical boxes. a resource of highly trained and expe- rienced scientists, engineers, and tech- Conclusion nicians who are available to support a Design of a DIRC Capability for The examples described above wide range of projects. The Labora- the GlueX Detector at Jefferson hopefully give the reader an idea of the tory welcomes inquiries concerning Laboratory capabilities of the Bates Laboratory in possible collaborations. The GlueX project at the Jefferson supporting a variety of experiments in Laboratory has as its goal the discov- nuclear and particle physics. The ex- References ery of new QCD states that are pre- amples are certainly not exhaustive, 1. R. G. Milner, Nucl. Phys. News 9(2) dicted by various models. A recent and new capabilities are regularly be- (1999) 4. planned upgrade to the GlueX detec- ing added. 2. M. Farkhondeh and V. Ptitsyn (eds,), tor involves the addition of a Detec- An important addition to the ca- BNL report C-A/AP/142, March 2004. tion of Internally Refl ected Cherenkov pabilities at the Bates Laboratory oc- light (DIRC) capability, especially to curred in 2009, when MIT made the enhance the ability to separate pions decision to locate a large High-Per- from kaons. The radiator for the DIRC formance Computing Facility at the uses four fi ve-meter long “bar boxes,” laboratory. This entailed repurposing each containing twelve fused silica space that had previously been used as bars. These bar boxes are recycled a large “counting house” where scien- from the BaBar detector that was built tists monitored equipment and data as previously at SLAC. nuclear physics experiments were un- The Bates Laboratory team is help- derway at Bates. Cooling capabilities ROBERT REDWINE ing with the DIRC construction by de- for the computer racks were installed, MIT, Cambridge, signing and building optical boxes that as this is a major need for such mod- Massachusetts, USA

Be sure to check the Calendar for upcoming events of interest to nuclear physicists.

6 Nuclear Physics News, Vol. 27, No. 4, 2017

feature article

Nuclear Symmetry Energy Extracted from Laboratory Experiments BAO-AN LI Department of Physics and Astronomy, Texas A&M University–Commerce, Commerce, Texas, USA

Introduction the Esym(ρ) around and below ρ0 while its high density The Equation of State (EOS) of uniform neutron-rich behavior remains rather uncertain. Combining results from nucleonic matter of isospin asymmetry δ =(ρn ρp)/ρ ongoing and planned new laboratory experiments with ra- and density ρ can be expressed in terms of the energy− per dioactive beams and astrophysical observations using ad- nucleon E(ρ,δ) within the parabolic approximation as vanced X-ray observatories and gravitational wave detectors has the great promise of pinning down the symmetry 2 4 E(ρ,δ)=E(ρ,0)+Esym(ρ)δ + o(δ ) (1) energy of dense neutron-rich matter in the near future.

2 2 where Esym(ρ)=1/2(∂ E(ρ,δ)/∂δ )δ=0 E(ρ,1) Important but Poorly Known Physics Underlying E(ρ,0) is the symmetry energy of asymmetric≈ nuclear mat-− Nuclear Symmetry Energy ter (ANM). It is approximately the energy cost of convert- It is well known that the nucleon potential Un/p(k,ρ,δ) ing symmetric nuclear matter (SNM, with equal numbers in ANM can be expanded up to the second order in δ as of protons and neutrons) into pure neutron matter (PNM). Uτ (k,ρ,δ)=U0(k,ρ)+τ3 Usym,1(k,ρ) δ +Usym,2(k,ρ) Many interesting questions including the dynamics of su- · · δ 2 + O(δ 3) (2) pernova explosions, heavy-ion collisions, structures of neu- · tron stars and rare isotopes, frequencies, and strain ampli- where τ3 = 1 for τ = n/p and k is nucleon momen- tudes of gravitational waves from both isolated pulsars and tum. At the mean-field± level, both the Bruckner theory and collisions involving neutron stars all depend critically on the Hugenholtz-Van Hove (HVH) theorem show that the the EOS of neutron-rich nucleonic matter. Thanks to the Esym(ρ) at an arbitrary density has two parts (kinetic and great efforts of scientists in both nuclear physics and astro- potential) [9] physics over the last four decades, much knowledge about 2 2 the EOS of SNM; that is, the E(ρ,0) term in Eq. (1), has 1 h kF 1 Esym(ρ)= + Usym,1(k,ρ) (3) been obtained [1]. In more recent years, significant efforts 3 2m0∗ 2 have been devoted to exploring the poorly known E (ρ) sym while its density slope L(ρ) 3ρ(∂E /∂ρ) has five parts using both terrestrial laboratory experiments and astrophys- ≡ sym ical observations. Essentially, all available nuclear forces 2 h¯ 2k2 1 h¯ 2k3 ∂m 3 ( )= F 0∗ + ( , ) have been used to calculate the Esym(ρ) within various L ρ 2 Usym,1 ρ kF 3 2m∗ − 6 (m∗) · ∂k 2 microscopic many-body theories and/or phenomenological 0 0 kF models. However, model predictions still vary largely at ∂Usym,1 + k + 3U , (ρ,k ), (4) both sub-saturation and supra-saturation densities although ∂k · F sym 2 F kF they agree often by construction at the saturation density 2 1/3 ρ . Therefore, accurate experimental constraints are imper- where kF =(3π ρ/2) is the nucleon Fermi momentum 0 m and m∗ = m/[1 + 2 dU0/dk)k ] is the nucleon isoscalar ative for making further progresses in our understanding 0 h kF F of the Esym(ρ). To facilitate the extraction of information effective mass. Obviously, the Esym(ρ) and L(ρ) depend about the Esym(ρ) from laboratory experiments, much work on the density and momentum dependence of both the has been done to find observables that are sensitive to the isoscalar U0 and Usym,2 as well as the isovector Usym,1 poten- Esym(ρ) by studying, for instance, static properties, excita- tials. While the U0 has been relatively well constrained by tions, and collective motions of nuclei as well as various ob- studying experimental observables in heavy-ion reactions, servables of nuclear reactions. Comprehensive reviews on especially various kinds of collective flow and kaon pro- the recent progress and remaining challenges in constrain- duction, our current knowledge about the density and mo- ing the Esym(ρ) can be found in the literature [2–8]. Most mentum dependence of the Usym,1(ρ,k) and Usym,2(ρ,k) is importantly, much progress has been made in constraining very poor.

Vol. 27, No. 4, 2017, Nuclear Physics News 7 feature article

It is important to point out that the Esym(ρ) is closely re- The momentum dependence of the isoscalar and isovec- lated to the neutron-proton effective mass splitting mn∗ p tor potential at ρ0 has been explored extensively using − ≡ (mn∗ m∗p)/m, which is a fundamental quantity having (p,n) charge-exchange and nucleon-nucleus elastic scatter- broad− impacts on many interesting issues in both nuclear ings. The resulting single-nucleon potential has been used physics and astrophysics. In terms of the momentum de- to constrain the Esym(ρ0) and L(ρ0). pendence of the single-nucleon potential or the Esym(ρ) and As an example, shown in Figure 1 are the kinetic 1 2 L(ρ), the mn∗ p is approximately Esym(ρ0) and potential Esym(ρ0) parts of Esym(ρ0) and the − five components [defined in Eq. (4)] of its slope L(ρ0) 2 2 2mδ ∂Usym,1 kF ∂ U0 1 ∂U0 m0∗ extracted from a recent analysis of large sets of nucleon- mn∗ p + − ≈ h2k − ∂k − 3 ∂k2 3 ∂k m nucleus elastic scattering data using an optical model [11]. F 2 The kinetic and potential parts of the symmetry energy from δ 1 m m∗ 3E (ρ) L(ρ) E (ρ) 0 this analysis are approximately equal. Among the five parts ≈ E (ρ) sym − − 3 m F m F 0∗ of the slope parameter L(ρ0), the L4 due to the momentum- dependence of the isovector potential and the L5 from where EF (ρ) is the Fermi energy in SNM. Therefore, while the second-order isoscalar potential have the largest uncer- probing the Esym(ρ), we are also studying the neutron- tainties. The characteristically decreasing isovector poten- proton effective mass splitting in neutron-rich nuclear mat- tial with increasing energy/momentum leads to a positive ter. It is well known that the kinetic symmetry energy is neutron–proton effective mass splitting and a negative value due to the Pauli blocking and the different Fermi momenta of L4 at ρ0. The mere fact that the L(ρ0) has five terms hav- of neutrons and protons. Since the nucleon isoscalar effec- ing different signs and physical origins indicates clearly the tive mass m /m 0.7 at ρ , the kinetic symmetry energy 0∗ ≈ 0 difficulties of completely pinning down the Esym(ρ) even of quasi-nucleons at ρ0 is about 43% larger than that of around the saturation density. the free Fermi gas of about 12 MeV frequently used in Given our poor knowledge about some components of the literature. The potential symmetry energy is due to the the L(ρ), no wonder why it is so difficult to determine ac- isospin dependence of the strong interaction. For example, curately the isospin dependence of the incompressibility the Hartree term of the isovector potential at k in the inter- 2 4 F of ANM K(δ)=K0 + Kτ δ + O(δ ) at ρ0 where Kτ = acting Fermi gas model can be approximated by Ksym 6L(ρ0) Q0L(ρ0)/K0 in terms of the curvature − − 2 2 2 of the symmetry energy Ksym 9ρ (∂ Esym(ρ)/∂ρ )ρ = 1 T1 ≡ 0 Usym,1(kF ,ρ)= ρ [VT1(rij) f (rij) 3[ρ∂L(ρ)/∂ρ L(ρ)] as well as the skewness Q and in- 4 − ρ0 0 compressibility K0 of SNM at ρ0. As the Ksym involves the V (r ) f T0(r )]d3r − T0 ij ij ij in terms of the isosinglet (T = 0) and isotriplet (T = 1) nucleon-nucleon (NN) interactions VT0(rij) and VT1(rij), and the corresponding NN correlation functions fT0(rij) and fT1(rij), respectively. While the charge independence of the strong interaction requires that Vnn = Vpp = Vnp in the T = 1 channel, they are not necessarily equal to the Vnp in the T = 0 channel. Obviously, if there is no isospin dependence in both the NN interaction and correlation function, then the isovector potential Usym,1 van- ishes. The momentum dependence of the isovector potential from the Fock term using Gogny-type finite-range, isospin-dependent interactions is often parameterized by using different strengths of interactions between like and unlike nucleons. Indeed, microscopic many-body theories predicted that the potential symmetry energy is dominated by the isosinglet interaction. It is also well known that 1 2 the short-range correlation in the T = 0 channel is much Figure 1. The kinetic Esym(ρ0) and potential Esym(ρ0) parts stronger than that in the T = 1 channel [10]. The potential of the symmetry energy Esym(ρ0) and the five components symmetry energy thus reflects the isospin dependence of [in the order of appearing in Eq. (4)] of its slope L(ρ0) nucleon–nucleon interactions and correlations in asymmet- extracted from an optical model analysis of the nucleon- ric nuclear matter. nucleus elastic scattering data. Taken from Ref. [11].

8 Nuclear Physics News, Vol. 27, No. 4, 2017 feature article

derivative ∂L/∂ρ, to determine its value we have to know Moreover, different clusters in the medium have their own not only the magnitudes but also the density and momen- local/internal isospin asymmetries and densities. Indeed, in tum dependences of both the isoscalar and isovector nu- terms of the average isospin asymmetry δav of the whole cleon potentials. Unfortunately, these quantities are largely system, the EOS of clustered matter has been found to have 2 unknown both theoretically and experimentally. As a result, odd terms in δav that are appreciable compared to the δav the current estimate of the value of Kτ = 550 100 MeV term. Thus, it is conceptually ambiguous to define a sym- from analyzing many different kinds of experimental− ± data metry energy for clustered matter in the same sense as for available still has a large error bar. It is also not surprising uniform nucleonic matter. that some of the best models available are having trouble reproducing the incompressibility of some neutron-rich nu- Constraints on Nuclear Symmetry Energy at the clei (e.g., Tin isotopes from 112Sn to 124Sn). Saturation Density The decompositions of Esym(ρ) and L(ρ) in Eqs. (3) and It is customary to characterize the density dependence (4) are transparent and useful for identifying the important of nuclear symmetry energy near ρ0 by using the Esym(ρ0) underlying physics. However, they have limitations. There and L(ρ0). In recent years, much progress has been made are density regions or phenomena for which correlations in constraining them using various observables from both beyond the mean-field level have to be treated properly. For terrestrial laboratory experiments and astrophysical obser- example, effects of the tensor force on the Esym(ρ) are av- vations. It is seen that the central values of the Esym(ρ0) eraged out at the mean-field level. However, tensor force and L(ρ ) scatter around E (ρ )=31.6 2.66 MeV 0 sym 0 ± induced short-range correlations may alter significantly the and L(ρ0)=58.9 16 MeV, respectively. As an exam- kinetic and potential contributions to the total symmetry en- ple, shown in Figure± 2 are values of the slope parameter ergy and its slope [7]. While how the total symmetry energy L(ρ0) from 28 analyses in the literature. Observables used is divided into kinetic and potential parts seems to have no in these analyses include the atomic masses, neutron-skins obvious effect on describing properties of neutron stars as of heavy nuclei, isospin diffusion in heavy-ion reactions, it is the total pressure and energy density that are needed excitation energies of isobaric analog states (IAS), isoscal- in solving the Tolman-Oppenheimer-Volkoff (TOV) equa- ing of fragments from intermediate energy heavy-ion colli- tion, it is certainly important for simulating nuclear reac- sions, the electric dipole polarizability from analyzing the tions using transport models describing the evolution of Pygmy dipole resonance, the frequency of isovector giant quasi-nucleons in phase space under the influence of nu- dipole resonances, α and β decay energies, optical poten- clear mean-fields and collision integrals. The strong isospin tials from analyzing nucleon-nucleus scatterings, and sev- dependence of the tensor force may even lead to vanishing eral observables of neutron stars, etc. Interestingly, the re- or negative Esym(ρ) at high densities, leading to the predic- sults in Figure 2 and from several other surveys indicate an tion of some interesting new phenomena in neutron stars empirical relation L(ρ0) 2Esym(ρ0). Theoretically, the lat- [12]. Indeed, going beyond the mean-field level, various mi- ter approximation becomes≈ exact when both the kinetic and 2/3 croscopic many-body theories that incorporate correlations potential symmetry energies are proportional to (ρ/ρ0) . to differing degrees have been used to predict the Esym(ρ). Unfortunately, the predictions still diverge broadly at supra- Constraining the Density Dependence of Nuclear saturation densities. Symmetry Energy Away from ρ0 The EOS of uniform and isospin-asymmetric nucleonic While the community has made significant advancement matter described by Eq. (1) and the definition of its sym- in constraining the Esym(ρ0) and L(ρ0), determining the metry energy have their ranges of validity too. For exam- density dependence of nuclear symmetry away from the ple, at low densities below the so-called Mott points, var- saturation density is more challenging. First of all, model ious clusters start forming. One thus has to go beyond the predictions are more diverse, especially at high densities mean-field by considering correlations/fluctuations and in- where the poorly known three-body force and possibly new medium properties of clusters in constructing the EOS of degrees of freedom become important. The density and mo- stellar matter for astrophysical applications. Then the Eq. mentum dependence of the underlying isovector potential (1) is obviously no longer valid. Moreover, there seems to determining the Esym(ρ) is also very model dependent. To be no need to introduce a symmetry energy of clustered experimentally probe the density dependence of nuclear matter for describing its EOS. In fact, for the clustered symmetry energy, one needs to study systematically static matter, because of the different binding energies of mir- properties of nuclei or dynamical observables describing ror nuclei, Coulomb interactions, different locations of pro- collective motions of nuclei or nuclear reactions. For ex- ton and neutron drip-lines in the atomic chart, the system ample, it is well known that in the nuclear mass/energy no longer possesses a proton–neutron exchange symmetry. formula of finite nuclei, the isospin asymmetry appears

Vol. 27, No. 4, 2017, Nuclear Physics News 9 feature article

Figure 2. Central values of L(ρ0) from 28 model analyses of terrestrial nuclear experiments and astrophysical observations. Taken from Ref. [13]. in both the volume and surface terms. Rewriting the nu- Among many interesting experiments, it is worth em- clear contributions to the energy of finite nuclei of mass phasizing that significant work has been done in constrain- number A as E(N,Z)=E (A)+a (A)(N Z)2/A where ing the E (ρ) using heavy-ion reactions at intermediate 0 asy − sym E (A)= a A+a A2/3 is the symmetric part of the energy energies. For example, several transport model analyses of 0 − v s in terms of the volume and surface energy coefficients av the experimental data on isospin diffusion between several and as, one can define the mass dependence of the sym- Sn isotopes taken by M.B. Tsang et al. at NSCL/MSU have metry energy coefficient as a (A) 1/av + A 1/3/as ] consistently extracted a constraining band on the Esym(ρ) asy ≡ asy − asy using the volume and surface symmetry energy coefficients between approximately ρ0/3 and ρ0 as shown with the grey v s aasy and aasy. The aasy(A) can be extracted from analyz- band in Figure 3. While at supra-saturation densities the ing atomic masses and/or excitation energies of the iso- data are very limited and various transport model calcula- baric analog states (IAS). By fitting the aasy(A) extracted from the IAS data with Skyrme-Hartree-Fock calculations, a constraining band on the Esym(ρ) between approximately ρ0/3 and ρ0 was obtained by P. Danielewicz and J. Lee as shown in Figure 3. Many reaction observables and phenomena ranging from cross-sections of sub-barrier fusion and fission at low energies, energy and strength of various collective modes, isospin diffusion, isoscaling, ratios and differential flows of protons and neutrons as well as mirror nuclei in heavy-ion reactions at intermediate energies, to hard photon, pion, kaon, and η production in nuclear reactions up to 10 GeV/nucleon have been proposed as promising probes of the Esym(ρ) (see, e.g., Refs. [2–8]). Most of these observables probe directly the density and momentum dependence of the single-particle potential. For example, the symmetry energy/potential plays the role of the restoring force for isovector collective modes of excited nuclei. Since the isovector potential is normally very small compared to the isoscalar potential, isospin-sensitive observables thus often Figure 3. Constraints on the density dependence of Esym(ρ) use relative or differential quantities/motions of neutrons from analyzing isospin diffusion, flow, and pion production and protons to enhance (reduce) effects of the isovector in heavy-ion reactions, isobaric analog states (IAS), prop- (isoscalar) potential. Depending on the conditions of the erties of double magic nuclei by B. A. Brown as well as reactions, these observables may probe the Esym(ρ) over a binding energies and neutron-skins of heavy nuclei by Z. broad density range. Zhang and L. W. Chen. Taken from Refs. [14, 15].

10 Nuclear Physics News, Vol. 27, No. 4, 2017 feature article

tions of reaction observables do not always converge. For range correlations in neutron-rich nuclei are being carried example, as indicated with the black arrow, analyzing the out or planned to better understand effects of the tensor + π−/π data from GSI taken by the FOPI collaboration us- force. Furthermore, new astrophysical observations, most ing a BUU-type (Boltzmann-Uehling-Uhlenbeck) transport noticeably the radii, frequencies of torsional oscillations, model by Xiao et al. [15], the Esym(ρ) was found to de- r-mode instability windows of neutron stars, neutrino flux crease with increasing density above about 2ρ0 as predicted from supernovae explosions, cooling curves of protoneu- by the Gogny-Hartree-Fock calculations. Later, the ASY- tron stars, gravitational waves from collisions involving EOS Collaboration analyzed the relative flows of neutrons neutron stars, and so on, also provide exciting new opportu- 3 w.r.t. protons, tritons w.r.t. He and yield ratios of light iso- nities for better constraining the Esym(ρ). Combining new bars using two versions of the QMD-type (Quantum Molec- information from both terrestrial nuclear experiments and ular Dynamics) transport models [14]. They found, instead, astrophysics observations will certainly allow us to deter- a Esym(ρ) continuously growing with density. As shown mine much more precisely the symmetry energy of neutron- clearly in Figure 3, there is a big disagreement regarding rich nucleonic matter in a broad density range. the high-density behavior of the Esym(ρ). Certainly, ongoing and planned new experiments coupled with more the- References oretical efforts using systematically tested reaction models 1. P. Danielewicz, R. Lacey, and W. G. Lynch, Science 298 will help improve the situation hopefully in the near future. (2002) 1592. 2. A. W. Steiner, M. Prakash, J. M. Lattimer, et al., Phys. Rep. Concluding Remarks and Outlook 411 (2005) 325. The density dependence of nuclear symmetry energy 3. V. Baran, M. Colonna, V. Greco, and M. Di Toro, Phys. Rep. Esym(ρ) is poorly known but very important for many in- 410 (2005) 335. teresting issues in both nuclear physics and astrophysics. 4. B. A. Li, L. W. Chen, and C. M. Ko, Phys. Rep. 464 (2008) Its accurate determination has broad impacts. Besides the 113. 5. M. B. Tsang et al., Phys. Rev. C86 (2012) 015803. challenges in treating nuclear many-body problems, our 6. C. J. Horowitz, E. F. Brown, Y. Kim, et al., J. of Phys. G41 poor knowledge about the isovector nuclear interaction is (2014) 093001. the main origin of the uncertain Esym(ρ). At the mean- 7. Topical Issue on Nuclear Symmetry Energy, Eds: B. A. Li, A. field level, the density and momentum dependence of both Ramos, G. Verde, et al., Euro Phys. J. A50(2) (2014). the isoscalar and isovector single-nucleon potentials af- 8. M. Baldo and G. F. Burgio, Prog. Part. Nucl. Phys. 91 (2016) fects the Esym(ρ) and L(ρ). Going beyond the mean-field 203. level, correlations and fluctuations, especially the short- 9. C. Xu, B. A. Li, and L. W. Chen, Phys. Rev. C82 (2010) range neutron–proton correlation due to the tensor force 054607. in the isosinglet channel also affects the symmetry energy 10. O. Hen et al., Science 346 (2014) 614. especially at supra-saturation densities. Besides possible 11. X. H. Li, B. J. Cai, L. W. Chen, et al., Phys. Lett. B721 (2013) phase transitions, the high-density symmetry energy has 101. 12. M. Kutschera et al., Acta Physica Polonica B37 (2006) 277. been the most uncertain part of the EOS of neutron-rich 13. B. A. Li and X. Han, Phys. Lett. B727 (2013) 276. nucleonic matter. 14. P. Russotto et al. (ASY-EOS Collaboration), Phys. Rev. C94 Thanks to the hard work of many people in both nuclear (2016) 034608. physics and astrophysics, much progress has been made 15. Z. G. Xiao, B. A. Li, L. W. Chen, et al., Phys. Rev. Lett. 102 in constraining the symmetry energy around and below (2009) 062502. the saturation density. In particular, rather consistent values of Esym(ρ0)=31.6 2.66 MeV and L(ρ0)=58.9 16 MeV have been obtained± from many analyses using± various kinds of data and models. However, the uncertain- ties of some of these analyses need to be better quanti- fied while the Esym(ρ) at supra-saturation densities remains rather uncertain. Looking forward, advanced radioactive beam facilities will allow reactions with higher isospin-asymmetries, thus enlarging the observable effects induced by the isovector nuclear interaction. Moreover, new experiments using electron-nucleus and (p,2pN) reactions at large momentum transfers investigating the isospin dependence of short- BAO-AN LI

Vol. 27, No. 4, 2017, Nuclear Physics News 11 feature article

Ion and Neutron Beams Discover New Facts from History Anna Macková1,2, Jan Kučera1, Jan Kameník1, Vladimir Havránek1, and Karel Kranda1 1Nuclear Physics Institute of the Czech Academy of Sciences, v. v. i., Husinec-Řež, Czech Republic 2Department of Physics, Faculty of Science, J.E. Purkinje University, Ústí nad Labem, Czech Republic

Introduction tage [6] that should remain intact after being exposed to Nuclear physics applications in medicine and energy are analytical investigation. Therefore, non-destructive meth- well known and widely reported. For example, the recent ods are of crucial importance for investigations. report “Nuclear Physics for Medicine,” published by the To this day, Neutron Activation Analysis (NAA) has European Science Foundation [1] or “Energy for the Fu- been mostly used at research reactors, which provide high- ture: The Nuclear Option,” written by scientists at the Eu- intensity neutron fields. In combination with high-resolu- ropean Physical Society (EPS) [2] can be mentioned. Less tion HPGe detectors complex g-spectra from irradiated ma- well known are the many important nuclear and related terial can be disentangled and the concentration of up to 45 techniques to study objects of cultural heritage. There has major and trace elements can be determined in one sample. been enormous progress in this field in recent years and our Although NAA usually requires placing a cultural-heritage current contribution provides some snippets of the compre- object (or a representative sample of it) for neutron irradia- hensive topical paper “Nuclear Physics for Cultural Heri- tion into the reactor, a chemical pre-treatment of the mate- tage” published by the EPS recently [3], which aims for a rial is not necessary. This procedure therefore preserves the popular and accessible account showing the broad nuclear original element composition of the object. physics applications in cultural heritage investigation and The Nuclear Physics Division of the EPS offers publi- preservation. Nuclear Physics contributes to archaeometry cation of the leading scientists in Europe, especially those mainly by non-invasive investigation of cultural heritage results derived from ion beams, neutron beams, dating objects with ion and neutron beams. methods, and many other nuclear analytical methods [3]. Developments of Ion Beam Analytical methods (IBA) Likewise, the publication offers exciting stories about many were related to progress in low-energy accelerators, in de- historical artefacts, paintings, papyrus, precious stones, an- tectors for particle, X-ray, and g ray measurements, and in cient jewelry, and the provenance of numerous artefacts systems for processing experimental data [4, 5]. Ion beams and ancient manufacturing technology. of several MeV, produced by small accelerators, penetrate into matter, interact with the atoms of the sample and produce, among other phenomena, X-rays and g rays, which How Do Ion and Neutron Beams Investigate Matter? provide information about the investigated artefacts. Small Ion Beam Analytical Techniques accelerators can generate a wide range of ion beams, with Although ion beam analysis was developed later than flexible energy range (and thus adjustable probed depth) other methods—simply because suitable accelerators only and diameter of the beam (from millimeter to micrometer became available in the second half of the 20th century, it size). Hence, such instruments can provide us with tailored is now the most versatile technique for investigating ob- tools for the study of the diverse objects of Cultural Heri- jects of cultural significance. A multitude of different ion

Archaeometry involves analytical and dating methods for object characterization. Nuclear physics contributes significantly to the dating methods (e.g., radiocarbon dating, thermoluminescence dating, optically stimulated luminescence dating) and to the analytical methods making possible to determine practically all the elements of the periodic table and enabling to reconstruct the spatial distribution of elements present in the sample.

12 Nuclear Physics News, Vol. 27, No. 4, 2017 feature article

are irradiated. The products of ion interactions with sample atoms are recorded with semiconductor detectors coupled to electronic devices for processing detector signals and data acquisition. PIXE and RBS are the most used methods for the comprehensive element analysis. Depending on the sample type and measuring apparatus, the concentration of elements with Z > 5 can be determined with PIXE down to about 0.1–1 μg.g–1. This method is not used for element depth profiling, because of its low depth resolution. The major advantage of PIXE’s use of ions is a reduction in the background activity when compared to those methods where electrons are used as the probe (electron microprobe induced X-ray emission). In the case of RBS, the depth profiling of Figure 1. The basic principles of ion beam analytical elements utilizes the defined charged particle energy losses methods. The probe ions with mass M are penetrating the in the investigated material with the depth resolution better sample and elastically back-scattered ions or elastically than 10 nm. For heavy elements, in a light substrate, the de- recoiled particles are recorded (upper part). Proton beams tection limits are about 0.01 atomic percent (at. %). are inducing X–ray or γ-ray emission based on inelastic In ion microprobe analysis, the samples are irradiated scattering with atoms or nuclear reaction, respectively with an ion beam focused to a quadratic spot of about 1 × 1 (bottom part). μm. Standard IBA techniques (PIXE, RBS) are used for the beam techniques is now available: NRA (Nuclear Reaction characterization of the irradiated part of the sample. Fig- Analysis), PIXE (Proton Induced X-Ray Emission), PIGE ure 3 displays an arrangement for ion microprobe analysis. (Proton Induced g-ray Emission), RBS (Rutherford Back- By scanning the beam within a defined window across the Scattering), and ERDA (Elastic Recoil Detection Analysis) surface of the sample a 3D distribution of elements can, in see Figure 1. principle, be determined with a nm depth resolution and a Standard equipment for IBA methods comprises an elec- lateral resolution limited only by the size of the beam spot. trostatic accelerator (Figure 2), generating ions such as pro- For this purpose, the signals detected are assigned to the x,y tons, deuterons, He, and heavier ions, with energies from coordinates of the beam spot [7]. 0.5–50 MeV. Such a facility also includes associated ion beam-lines and vacuum target chambers where the samples

Figure 3. Microbeam arrangement at Tandetron accelera- Figure 2. Tandetron accelerator with ion beam-lines, vac- tor (CANAM, Nuclear Physics Institute of the Czech Acad- uum chambers, and detectors used for the various nuclear emy of Sciences, the Czech Republic), the vacuum chamber analytical methods in Center of Accelerators and Nuclear for placing specimen on the right and magnetic quadrupole Analytical Methods (CANAM), Nuclear Physics Institute of triplet lenses for focusing the beam to micrometer size on the Czech Academy of Sciences, the Czech Republic. the left.

Vol. 27, No. 4, 2017, Nuclear Physics News 13 feature article

In order to measure the distribution of elements along NAA with relative standardization has recently been recog- a line, or map the elemental distribution over an area, the nized as a primary method of measurement (e.g., a method sample must be scanned with the focused beam spot and the with the highest metrological properties [9]). detector signal recorded as a function of the displacement of the beam from its normal position. When a beam of ions scans an area of a specimen, the emitted radiation carries What Can We Discover? information in three degrees of freedom—the two spatial Pigment and Body Composition of Chinese Ming Pottery dimensions (x,y coordinates) and the energy [7]. Scanning Found in Angkor ion microprobe (SIMP) and scanning proton microprobe The purpose of the investigation was to determine the are very useful techniques for in situ element or isotope possible origin of Chinese pottery sherds, presumably dat- distribution analysis. ing to the Ming dynasty found in excavated material from In practice, materials or artefacts often cannot be placed an ancient pool at the Royal palace grounds of Angkor in a vacuum chamber because of their large size or the pres- Thom. As the former imperial city was abandoned shortly ence of volatile components. Such samples can be analyzed after its sack by the Thai armed expedition in 1431 the ar- with an external ion beam. Such a beam consists of ions tefacts found on the grounds probably had been imported that pass through a thin window from the vacuum to the air by the Royal court while still at Angkor Thom. It was our environment. In a standard arrangement, the beam spot at intention to separately analyze the composition of the glaze the target is a millimeter or less in diameter if the beam is and the painted sections containing cobalt (Figures 4a and shaped by slits, but it can reach 10 or 30 μm if the beam is b). Furthermore, we attempted to find the possible origin focused with suitable magnetic optics [8]. of the kilns in China where the sherds found were actually manufactured. Hence, we compared the characteristic trace Neutron Activation analysis element content in the sherds body determined by macro Neutron activation analysis is a multi-elemental analyti- PIXE and the composition of the cobalt pigment inclusions cal technique used for qualitative and quantitative analysis determined by µ-PIXE with reported measurements of ele- of major, minor, and trace elements. Samples weighing, mental composition of ancient Chinese porcelain produced typically in the range from sub-mg to g, are irradiated with at various kiln locations in China [10]. The shards, cuts, and neutrons and the newly formed radioisotopes are created, corresponding µ-PIXE maps are shown in Figures 4c and d. mostly via the (n,γ) nuclear reaction with thermal neutrons The sherds were sliced to thin sections and examined (neutron radiative capture). The radioactive decay of newly with a microscope coupled to a camera to identify the ele- formed radionuclides is often accompanied by the emission ments of the cobalt-pigment decorations and the glaze. The of characteristic γ-rays. The irradiation is usually carried samples were placed in aluminium holders and irradiated out at a nuclear reactor but other neutron sources (radioiso- with a proton beam that was focused to a 1 micrometer spot topic or accelerator based) can also be used. The neutrons with an Oxford triplet quadrupoles (Figure 3). Both the used for irradiation are categorized as cold, thermal, epith- macro- and micro-PIXE analyses were done on the same ermal (resonance) or fast, according to their energy. In gen- samples. The proton beam energy of a Tandetron accel- eral, the lower the neutron energy, the higher the probability erator was varied between 2 and 3 MeV according to the of the neutron radioactive captures. Detection limits are pri- atomic mass of the elements desired for investigation in a marily determined by neutron capture cross-sections; that particular experimental session. is, the probability of the (n,γ) reaction, neutron flux, abun- Up to 20 elements were typically determined during dance of the target isotope and the measured characteristics each macro PIXE measurement with sufficient detection of the emitted radiation. NAA can detect up to 74 elements limits to determine trace content of Cu, Zr, Rb, and Y, nec- depending on the experimental procedure, with minimum essary for sherds source appointment. From the µ-PIXE detection limits ranging from 10–7 to 10–12 g g–1, depend- analysis the maps of individual elements were constructed ing on the element and matrix composition. The NAA tech- from their emission spectra showing a space-resolved con- nique requires a small sample to be taken from the object centration of each particular element. The examples of Ca analyzed (e.g., by drilling in an inconspicuous place) but and Co element distributions can be seen in Figure 4c and the size of the sample is usually so small that damage to the d. The advantage of the measurements reported here is their object is minimized. Thanks to its high potential for accu- superior spatial resolution, which enabled us to target the racy and well defined theoretical background (all sources of individual pigment spots and reduce the partial volume ef- uncertainty can be experimentally evaluated or modelled). fects of wider beam measurements. Our sample analysis

14 Nuclear Physics News, Vol. 27, No. 4, 2017 feature article

(a) (b)

Figure 4. Cobalt blue sherds found in the excavated sediments from the pool of the Royal palace in Angkor Thom (a, b). PIXE analysis using an incident proton ion beam of 2 MeV using a microbeam provided 2D element maps of Co (c) in the blue pigment and Ca content (d) of the glaze (bottom) on the sherd cross-section (top). found Ca values similar to those reported for Chinese pot- Was He Murdered or Was He Not? tery of the Ming dynasty. Determination of Mercury in the Remains of Tycho Brahe Microbeam measurement of the sherds cross-section World-renowned Renaissance astronomer Tycho Brahe clearly distinguished the glaze on the shards, as calcium (Figure 5) died on 24 October 1601, after 11 days of sud- content is much higher in the glaze (see Ca 2D elemen- den illness. Several conspiracy theories, namely mercury tal maps in Figure 4d). From the comprehensive elemental poisoning, had been aired shortly after his death. To test analysis of about 20 elements in the glaze, body, and cobalt the murder hypothesis, Brahe’s grave in Prague was re- pigment, it appears that the pigment was most likely im- opened in 2010 and samples of his bones, hair, teeth, and ported from Persia and that the shards analyzed were manu- the textiles were collected and analyzed. For NAA, hairs factured in kilns at two distinct locations in China [11]. with identifiable roots were cut into ~5 mm long sections.

Vol. 27, No. 4, 2017, Nuclear Physics News 15 feature article

the health and professional status of a particular person. The element map of Fe in Figure 6a shows external contamination of the hair specimen analyzed, demonstrating that μ-PIXE could distinguish between the elements present on the hair surface and those homogeneously distributed in the hair matrix, like S in Figure 6b. Figure 7 shows an excellent agreement between the NAA and μ-PIXE results for one hair sample from Tycho Brahe. These values were found to be comparable to the median and ranges of Hg contents in the contemporary non-exposed population. Hair provides a lasting record of exposure to trace metals over the last few months of life. The hair samples analyzed in this study relate to the Hg in- take over approximately the last 2 months prior to the death of Tycho Brahe, assuming the most frequently cited hair growth rate of 10 mm per month [13]. The highest Hg values found in Brahe´s hair are slightly above the median of ”normal“ values but are still within the normal range. The Hg concentration decline along the hair length indicates that Brahe was not exposed to any exces- sive Hg doses shortly before his death (Figure 7). Analysis

(a)

Figure 5. Tombstone from the grave of Tycho Brahe (1546– 1601) situated at the Church of Our Lady before Týn, Prague, the Czech Republic.

The sectioned hair samples from 20–25 individual hairs weighing 200–300 µg were sealed in pre-cleaned high-purity quartz ampoules and irradiated in the LVR-15 nuclear reactor in Řež (operated by Research Centre Řež, Ltd.) at a thermal neutron fluence rate of 3 × 1013 cm–2 s–1 for 20 h. 203 The Hg radionuclide formed was chemically separated (b) after 2–3 weeks of decay using an NAA procedure [12], based on Hg extraction with 0.01 mol L–1 Ni diethyl di- thiocarbamate (Ni(DDC)2). The extract was measured with high-resolution gamma-spectrometry. Unsectioned hair samples were also analyzed by μ-PIXE, using a Tandetron 4130 MC accelerator with a 2.6 MeV proton beam focused to a diameter of 1.5 µm. Mul- tiple scans were performed over 500 µm sections of hair at a 0.1 nA beam current for 1–3 h (Figure 6a and b to follow the concentration of trace and matrix elements with special focus on Hg concentration). The concentrations and the spatial distributions of the other elements are also important, as these may provide some information on a possible Figure 6. PIXE 2D elemental map of middle part of hair for hair surface contamination, hair aging process and reveal different elements Fe (a) and S (b).

16 Nuclear Physics News, Vol. 27, No. 4, 2017 feature article

4. J. R. Tesmer and M. Nastasi, Handbook of Modern Ion Beam Materials Analysis (Material Research Society, Pittsburgh, PA, 1995). 5. A. Macková and A. Pratt, Ion/Neutral Probe Techniques, Handbook of Spectroscopy: Second, Enlarged Edition (Wiley- VCH Verlag GmbH & Co. KGaA, Weinheim, 2014). 6. J.-C. Dran et al., Nucl. Instr. and Meth. in Phys. Res. B 219– 220 (2004) 7. 7. L. E. Murr, Electron and Ion Microscopy and Microanaly- sis: Principles and Applications (Marcel Dekker, New York, 1991). 8. L. Giuntini, Anal. Bioanal. Chem. 401 (2011) 785. 9. R. R. Greenberg, P. Bode, E. A. de Nadai Fernandes, Spectro- chim. Acta Part B 66 (2011) 193. Figure 7. Time course of Hg contents in one sample of Ty- 10. P. L. Leung and H. Luo, X-Ray Spectrom. 29 (2000) 34. cho Brahe’s hair. 11. K. Kranda, V. Havránek, V. Peřina, et al.. On the Composition of Cobalt Pigment of Chinese Ming Pottery Found In Angkor, TECHNART 2011—Berlin, 26–29 April 2011. of Brahe’s bones revealed no long-term exposure to Hg (no 12. J. Kučera and L. Soukal, J. Radioanal. Nucl Chem. 168 chronic poisoning). Thus the analyses carried out falsify the (1993) 185. hypothesis that the famous astronomer was poisoned by Hg 13. K. L. Rasmussen, J. Kučera, L. Skytte, et al., Archaeometry and his presumed murder is nothing but a fiction. 55 (2013) 1187.

Conclusions The application of atomic and nuclear techniques to studying archaeological objects provides a historian or archaeologist with hard data that can facilitate our understanding of the past. This knowledge is necessary for testing the authenticity and provenance of ancient artefacts. In some cases, the data of spatially resolved element analysis provide useful information for decision to be made about the restoring approach to be taken. These objectives are presumably already shared by the majority of people work- Anna Macková Jan Kameník ing in the field of archaeometry. In general, once it becomes accepted that from more detailed studies of the past we may learn more about the present, it seems likely that the desire to better understand our cultural heritage and the need to protect it will grow.

References 1. F. Azaiez, A. Bracco, J. Dobeš, et al. (eds.), Nuclear Physics for Medicine, Nuclear Physics European Collaboration Com- mittee (NuPECC) (2014), http://www.nupecc.org/npmed/ Vladimír Havránek npmed2014_hires.pdf 2. H. Freiesleben, R. C. Johnson, O. Scholten et al., Energy for Jan Kučera the Future: the Nuclear Option, Position Paper of the Euro- pean Physical Society (2007), http://c.ymcdn.com/sites/www. eps.org/resource/resmgr/policy/eps_pp_option_2007.pdf 3. A. Mackova, D. MacGregor, F. Azaiez, et al. (eds.), Nuclear Physics for Cultural Heritage, Topical paper of the Nuclear Physics Board of the EPS (2016), http://www.edp-open.org/ images/stories/books/fulldl/Nuclear-physics-for-cultural- heritage.pdf Karel Kranda

Vol. 27, No. 4, 2017, Nuclear Physics News 17 facilities and methods

The Institute for Nuclear and Radiation Physics at the University of Leuven

Introduction and Brussels joined efforts to build whereby the IKS researchers were not Last year some two hundred pres- the first post-accelerated ISOL facil- only frequent users but also signifi- ent and former collaborators came to ity, starting reaction studies of astro- cantly contributed to long-term strat- Leuven to celebrate the fiftieth an- physical interest using radioactive ion egies and projects at some of these niversary of the Instituut voor Kern- beams. On the other hand, besides large-scale facilities within interna- en Stralingsfysica (IKS; Institute for the standard hyperfine techniques for tional collaborations. Nuclear and Radiation Physics). The solid-state physics, Rutherford back- In a very natural way, two general institute originated in the slipstream scattering and channeling experiments lines of research have emerged from of the separation of the Catholic Uni- started at the Van de Graaff accel- the growth of IKS, namely nuclear versity of Leuven into two parts: the erator in Louvain-la-Neuve but were structure and reaction physics, and Flemish KU Leuven, remaining in the soon continued at the 1.7 MV Tandem nuclear solid-state physics. While the city of Leuven and the French Uni- Pelletron at imec (the Interuniversity collaboration between the different versité Catholique de Louvain, situ- Micro-Electronics Center, Leuven) research groups has remained strong, ated in the new town of Louvain-la- and finally in 1994, in-house, in a the different pace of those fields has Neuve. The IKS started in 1967 with new laboratory, the Ion and Molecular also lead to many independent devel- two professors, two Ph.D. students, Beam Laboratory (IMBL) (Figure 1). opments. and three technicians. Its physics pro- Next to the local activities (Leu- gram was influenced by the work of ven and Louvain-la-Neuve) a strong Nuclear Structure and Professor Erwin Bodenstedt at the In- program was also developed at inter- Reaction Physics stitut für Strahlen-und Kernphysik of national facilities such as ISOLDE- The fundamental understanding of the Universität Bonn. It concentrated CERN, GSI-Darmstadt, GANIL- nature is the driving force behind most on the measurement of magnetic mo- Caen, PSI-Villigen, ESRF-Grenoble, of the research in nuclear physics. At ments of excited nuclei using radioactive ion implantation and hyperfine techniques such as perturbed angular correlation, Mössbauer spectroscopy, and nuclear orientation. Although in the beginning solid-state physics issues related to implantation were treated as secondary but necessary input for the nuclear physics questions, it developed soon as an independent, complementary research line. In 1970, an off-line separator for long lived radioactive isotopes was installed in Leuven (LIS—the Leuven Isotope Separator) while in 1974 the Leuven Isotope Separator On Line (LISOL) was installed at the CYCLONE cyclotron in Louvain-la-Neuve. The scientific focus of LISOL was on moment measurements, detailed β-decay studies, and decay spectroscopy of nuclei far from stability. In 1986 the universities of Louvain-la-Neuve, Leuven, Figure 1. Layout of the Ion Molecular Beam Laboratory.

18 Nuclear Physics News, Vol. 27, No. 4, 2017 facilities and methods

IKS, we challenge our understanding of the weak interaction or of the strong force in exotic nuclear systems. In both aspects, modern experimental re- quirements are high, in order to work with short-lived, exotic nuclei as well as developing state-of-the-art systems to manipulate and study the nucleus.

Selective Production of Radioisotopes for Decay Spectroscopy The study of radioactive ion beams is heavily linked to their availability. This is why IKS has a long history of research into their production. For example, LISOL used proton- and heavy-ion-induced reactions on thin targets in a gas catcher in combination with resonant laser ionization to study Figure 2. The laser setup in the HELIOS laboratory. (Source: Marilyn De Smet- the decay of isotopes from elements aboutmary.be) out of reach of many other ISOL facilities, such as refractory and metallic Resonant Ionization Laser Ion Source nal techniques at the LISOL separator ions. The study of ground-state prop- (RILIS) collaboration at ISOLDE before bringing its knowledge to the erties with in-gas laser spectroscopy for radioactive elements such as po- COLLAPS collaboration at ISOLDE was also made possible for 57Cu or lonium and astatine. These develop- [2]. IKS took a special interest in the 97Ag, both isotopes that allowed prob- ments are key to an important survey island of inversion near N = 20 as ing nuclear structure in the vicinity of the ground-state properties from well as in the vicinity of magic num- of doubly closed shell nuclei, namely 79Au to 85At. In parallel, an extensive bers, like Z = 28 and Z = 50. In order 56Ni and 100Sn. A new milestone was study of β-delayed fission in that re- to push those studies to more exotic recently reached by performing the gion revealed fission fragment dis- systems, a higher level of sensitivity resonant laser ionization in the super- tributions that were at odds with the was necessary; this was achieved first sonic gas jet exiting the gas catcher, in- intuitive understanding of the process by the introduction of bunched-beam stead of inside the gas volume, hereby and have sparked a lot of theoretical laser spectroscopy, and then finally reducing the broadening suffered by studies. Finally, IKS is one of the driv- by combining the collinear laser spec- the atomic transitions of interest with- ing forces behind the ISOLDE Decay troscopy with resonant ionization at out any loss in efficiency [1]. This Station (IDS) program, a new modu- the CRIS experiment [3]. new avenue of research is now under lar experiment at ISOLDE that offers Not all isotopes are, however, di- full study at the new in-house Heavy many opportunities for the study of rectly accessible by laser spectros- Element Laser IOnization Spectros- decay spectroscopy. copy. For the study of the island of copy (HELIOS) laboratory (Figure inversion around N = 20, a research 2), in preparation for the study of very High-Resolution Study of program making use of β-NMR and heavy and super heavy elements at the Ground-State Properties β-NQR has been developed at the Super Separator Spectrometer (S3) at In collinear laser spectroscopy, a LISE spectrometer at GANIL. GANIL-SPIRAL2. traveling beam is overlapped with The IKS research program also cov- laser radiation. Thanks to the accel- Fundamental Interactions in ers the region of Z = 82 and N = 104, eration process, the velocity distribu- Subatomic Particles midway between N = 82–126, where tion is forward-focused and the ion- The angular correlation between shape coexistence is found at low en- source broadening disappears. IKS the β-particle and the polarized nu- ergy. Developments of laser ionization has participated for many years in clear spin or the neutrino are being schemes were made together with the laser spectroscopy, developing origi- studied with 35Ar and the β-delayed

Vol. 27, No. 4, 2017, Nuclear Physics News 19 facilities and methods

proton decay of 32Ar, respectively, transfer reactions have also been per- experiments often requires a profound thereby probing scalar or tensor type formed to study the island of inversion theoretical analysis. From the early weak interaction forms. Earlier stud- near N = 20 and in the Z = 28 region 1990s on, a variety of ab initio, Monte ies of this type have been performed [8]. The new HIE-ISOLDE post-ac- Carlo, and molecular dynamics codes with the NICOLE and WITCH setups celerator, with increased beam energy, entered the lab, and ever since these at ISOLDE [4, 5]. Other approaches will allow to further this program computational approaches [10] have are also being investigated using the by reaching higher excited levels in become indispensable. LPC Trap setup at GANIL. Coulomb excitation and higher cross During the past 50 years, the mate- This program is complemented sections in transfer reactions. The re- rials under investigation have signifi- with the search for the neutron electric action study program is completed by cantly changed. Often driven by major dipole moment, a property that would extensive new developments into new challenges in (micro-electronics) tech- highlight physics beyond the Standard technologies, such as the active targets nology—but always aiming at under- Model. This search is carried out with (ACTAR, SpecMAT) and the ISOL standing the fundamental interactions the nEDM experiment, originally de- Solenoid Spectrometer (ISS). and processes underlying the sys- signed at the Institut Laue-Langevin tems—our research has focused on thin (ILL) in Grenoble (France) [6] and Nuclear Solid-State Physics films, interfaces, surfaces, and nano- now carried out at the Paul Scherrer As pointed out in the introduc- structures. Indeed, due to their very Institute (PSI) in Villingen (Switzer- tion, it was very soon realized that local interaction, both hyperfine and land). After a successful first study hyperfine interactions could not only ion techniques are ideally suited for in- that has reached the highest sensitiv- be used to study nuclear properties, vestigating small systems. The general ity on this observable, the nEDM ex- but in a reverse approach enable one goal is to understand the intimate link periment is currently undergoing an to investigate the electronic, struc- between the structure of a material and upgrade to push further the sensitivity tural, and magnetic properties of the its functional properties, in particular limit. The IKS contribution lies in the environment of a (known) nucleus. when reducing the size below a critical coordination of one of the two analy- Based on this strategy, a strong solid- length. Throughout the years, a number sis teams and the precise monitoring state physics research program was of trends have emerged. and stabilization of the magnetic field set up, mainly based on Mössbauer within the setup with magnetometry spectroscopy (MS), perturbed angu- Trend 1: The Need for techniques developed at IKS. lar correlation (PAC) spectroscopy, Complementary, Non-nuclear and low-temperature nuclear orienta- Characterization Post-Accelerated Radioactive tion (LTNO). At the heart of these ex- Unlike many of the early studies, it Ion Beams periments was the LIS off-line isotope is no longer possible to capture (and IKS also has a long tradition of separator, which delivered a variety understand) the full picture based on studying nuclear reactions with post- of long-lived radioactive “spy” ions hyperfine or ion interactions alone. accelerated beams. In the wake of the with energies up to 100 keV. A disad- Little by little, complementary tech- successful study of post-accelerated vantage of using ion implantation for niques for synthesizing and analyz- 13N at the CRC, which started in 1986, radioactive doping—also in nuclear ing low-dimensional samples were a large nuclear astrophysics and struc- physics studies—are the irradiation- added, ranging from molecular beam ture program was carried out at this induced damage to the host and the epitaxy (MBE) to scanning tunnel- facility for 20 years. Meanwhile, the often unknown lattice site of the probe ing microscopy (STM) and X-ray research program has diversified to atom. These challenges triggered a diffraction (XRD). In 1994, the ma- many facilities and many techniques, broadening of the solid-state research jority of the equipment was brought like in the MiniBall Collaboration, from merely hyperfine interactions together and coupled in vacuo in the where Coulomb excitation experi- to ion–solid interactions [9], and in- IMBL (Figures 1 and 3), which cur- ments are carried at safe energies in dicated the start of a broad ion beam rently comprises two MBEs, two ion the region of Z = 28 and N = 40–50, research program, including ion im- implanters and a Pelletron accelerator, as well in the region of the neutron- plantation, ion irradiation, ion beam along with a wide range of surface and deficient lead isotopes [7]. By com- synthesis, and ion beam analysis. Fi- thin film characterization techniques. bining the MiniBall germanium detec- nally, it became clear that full under- During the past decades, the IMBL tor array with the T-REX silicon array, standing of the hyperfine or ion beam has played a crucial role in studies of

20 Nuclear Physics News, Vol. 27, No. 4, 2017 facilities and methods

14.4 keV photons (i.e., the 57Fe Möss- bauer transition) of a synchrotron allows one to probe magnetic properties as a function of depth (using a wedge sample) or as a function of pressure (using a diamond anvil cell). More- over, capturing the inelastic scattering allows to investigate phonons in nano- structured systems. Hence, it is clear that nuclear solid- state research has moved a long way during the past 50 years, from pure hyperfine studies in the early days, to very broad characterization platforms nowadays.

Future Perspectives The integration of the different Figure 3. Doctoral students working the Ion Molecular Beam Laboratory. research avenues and the interaction (Source: Layla Alerts, www.laylaaerts.be) between the different themes has been key to the strength of IKS in the last (magnetic) multilayers [11], surface low implantation energies (down to 5 50 years. It remains a driving force diffusion [12], silicides [13], and dop- eV, resulting in “implantation” on a of this institute and new projects are ing of materials [14]. In particular, the surface) or short-lived isotopes [16], emerging from recent developments. capability to deposit (sub)monolayers or ion beam analysis during a thin At ISOLDE, a new laser polar- of enriched isotopes (e.g., for MS or film reaction [17]—all need on-line ization beam-line has been commis- LTNO) allows probing the properties characterization. To this end, experi- sioned to serve a variety of research as a function of depth—from the sur- ments allowing in situ sample growth, themes: study of oriented nuclei for face down to the interface. Recently, a modification, and characterization fundamental decay studies with 31Ar, strategic decision was taken to group have been set up at LIS, the IMBL, biomolecular studies with metal ions, state-of-the-art infrastructure in the ISOLDE, and iThemba LABS. Al- and surface interactions probed with Leuven NanoCentre, where we have though the stringent boundary condi- radioactive nuclei deposited by soft installed atom probe tomography tions drastically enhance the level of landing with the ASPIC setup. (2016) and focused ion beam (2017) complexity, the unique capabilities are The effort invested into radioactive on vibration-controlled floor, allowing most often extremely rewarding. ion beam production and purification for 3-D compositional characteriza- will be valorized in the new CERN tion with sub-atomic resolution. A ma- Trend 3: The Need for MEDICIS facility (MEDical Isotopes jor fraction of the analysis is done in Large-Scale Facilities Collected from ISolde), offering regu- close collaboration with the Materials Whether it concerns short-lived lar radioisotope delivery for novel nu- Characterization group in imec. or exotic radioactive ions (for MS clear medicine. A collaboration with or emission channeling), polarized local research hospitals and a larger Trend 2: From “Stand-Alone” neutrons (for probing structure and European network will promote the toward “On-line,” “In Situ,” or magnetism in thin films), or high-bril- use of the ISOL method for nuclear “Real Time” Experiments liance (focused) photons (for nuclear medicine toward developing new Studies on ultra-small samples or resonant scattering, the time-domain targeted therapy treatments and PET- ultra-thin films (which require keep- equivalent of MS), large-scale facili- aided hadron therapy [19]. ing the sample in vacuum throughout ties such as ISOLDE, ILL or HZB, and IKS is investing in some of the the experiment), at very low tempera- ESRF or APS, have been playing an new, large-scale, European projects tures (including implantation in fro- important role in our studies [18]. Just in nuclear physics: HIE-ISOLDE and zen noble gases [15]), using extremely as an example, the capability to focus SPIRAL2, both quite advanced in

Vol. 27, No. 4, 2017, Nuclear Physics News 21 facilities and methods

their construction, and in the ISOL@ References MYRRHA project at the SCK•CEN- 1. R. Ferrer et al., Nat. Comm. 8 (2017) Mol. It is a member of the Belgium 14520. EURISOL Consortium, supporting the 2. L. Vermeeren et al., Phys. Rev. Lett. 68 EURISOL Distributed Facility and the (1992) 1679. EURISOL project. 3. R.P. de Groote et al., Phys. Rev. Lett. 115 (2015) 132501. IKS is now a full-grown research 4. G. Soti et al., Phys. Rev. C 90 (2014) institute hosting nine full-time pro- 035502. fessors and three 10% professors; 21 5. P. Finlay et al., Eur. Phys. J. A 52 THOMAS ELIAS COCOLIOS postdocs, senior scientists, and en- (2016) 206. KU Leuven, Physics & Astronomy, gineers; and 30 Ph.D. students. The 6. M. Pendlebury et al., Phys. Rev. D 92 Institute for Nuclear & Radiation research portfolio contains nuclear (2015) 092003. Physics, Leuven, Belgium structure physics focused on exotic 7. N. Bree et al., Phys. Rev. Lett. 112 nuclei, and nuclear solid-state phys- (2014) 162701. ics focused on ion–solid interactions. 8. J. Diriken et al., Phys. Lett. B 736 The goals of our research are to under- (2014) 533–538. 9. E. Verbiest et al., Nucl. Instr. Meth. stand the strong and weak interaction 182 (1981) 515. in the nuclear medium and to unravel 10. S. Cottenier and H. Haas, Phys. Rev. B the link between the structure of a 62 (2000) 461. material and its functional properties. 11. J. Meersschaut et al., Phys. Rev. Lett. Moreover, there is a strong awareness 75 (1995) 1638. of the impact our research can have 12. K. Paredis et al., Appl. Phys. Lett. 92 (2008) 043111. on neighboring fi elds such as atomic MARK HUYSE physics and nuclear astrophysics, and 13. M.F. Wu et al., Appl. Phys. Lett. 67 KU Leuven, Physics & Astronomy, (1995) 3886. on possible applications such as the Institute for Nuclear & Radiation 14. L.M.C. Pereira et al., Appl. Phys. Lett. development of novel medical radio- Physics, Leuven, Belgium isotopes. 98 (2011) 201905. 15. M. Vanderheyden et al., Phys. Rev. B 36 (1987) 38. Acknowledgments 16. U. Wahl et al., Phys. Rev. Lett. 118 The research from our institute (2017) 095501. has been made possible thanks to the 17. J. Demeulemeester et al., Appl. Phys. support from KU Leuven, as well as Lett. 93 (2008) 261912. 18. S. Couet et al., Adv. Funct. Mat. 24 regional, national, and European sup- (2014) 71. port from the following agencies: 19. L. Buehler, T.E. Cocolios, J. Prior, T. Belspo, the European Commission, Stora, CERN Courier 56 (2016) 28. FWO, Hercules, IIKW, IWT. ANDRÉ VANTOMME KU Leuven, Physics & Astronomy, Institute for Nuclear & Radiation Physics, Leuven, Belgium

View current and forthcoming book titles at:

22 Nuclear Physics News, Vol. 27, No. 4, 2017 facilities and methods

Nuclear-Physics Experiments at the Bremsstrahlung Facility γELBE

The setup for experiments with The bremsstrahlung facility [1] positioned at angles of 90° and two electron bremsstrahlung is one of the uses the electron beam behind the at 127° relative to the beam direction. beam-lines at the Center for High- first accelerator module, where a All detectors are surrounded by es- Power Radiation Sources of Helm- maximum electron energy of about 18 cape-suppression shields made of bis- holtz-Zentrum Dresden-Rossendorf, MeV is available in connection with muth germanate (BGO) scintillation Germany. The heart of the center is a a maximum average current of about detectors. It should be emphasized superconducting electron linear accel- 0.7 mA, and the accelerator is oper- that the materials of the components erator of high brilliance and low emit- ated in continuous-wave (cw) mode of the setup, such as the collimator, tance (ELBE). Generated in a therm- with a repetition rate of 13 MHz. Part the evacuated beam tube, the alumi- ionic gun, the electron beam passes the of the beam-line and the experimen- num detector stands and the photon subsequent main accelerator modules. tal cave are depicted in Figure 2. To beam dump, were chosen such that the The floorplan in Figure 1 shows the produce bremsstrahlung, the electron scattering of g radiation into the detec- various beam-lines for the production beam hits a niobium foil of selectable tors and the production of neutrons of secondary radiation around the ac- thickness between 2 and 12 mm. Be- via (g,n) reactions are largely sup- celerator. In addition to the beam-line hind the radiator foil, a 2.60 m long pressed. The beam characteristics of for bremsstrahlung (gELBE), there collimator of pure aluminum, installed the ELBE accelerator in combination are facilities for the production of in the concrete wall between the accel- with the efficient detector setup in a positrons (pELBE) with systems for erator hall and the experimental cave, low-background environment provide monoenergetic positron spectroscopy, forms a g beam from the bremsstrah- unique conditions for nuclear-physics for the production of fast neutrons lung cone. In the experimental cave, experiments with bremsstrahlung and with a time-of-flight system (nELBE), the g rays travel in an evacuated beam- for experiments on positron-annihila- two free-electron lasers (FELBE), and line before being dumped in a poly- tion lifetimes [2]. A photograph of the a THz source (TELBE). The electron ethylene block, surrounded by a cad- setup is shown in Figure 3. beam is directly used, for example, for mium foil and a layer of lead bricks. detector tests with a high time resolu- The target to be studied is mounted in Photoexcitation of Nuclei tion. Also, the ELBE building houses the beam tube. g rays scattered from The excitation and deexcitation of high-power lasers for experiments the target are measured with four atomic nuclei by electromagnetic ra- on laser-particle acceleration, also in high-purity (HPGe) detectors of 100% diation are fundamental processes in combination with the electron beam. relative efficiency. Two of them are reactions of this many-body quantum

optical labs free-electron lasers

neutron neutron PW exp. area lab time-of-flight

accelerator hall THz facility laser electron acceleration

g rays x-ray 500TW laser Draco accelerator electronics electrons lab positron laser lab laser ion acceleration

PW DPSSL Penelope Figure 1. Floorplan of the ELBE Center for High-Power Radiation Sources.

Vol. 27, No. 4, 2017, Nuclear Physics News 23 facilities and methods

dipole quadrupole This E1 strength is often referred to as quadrupoles a pygmy dipole resonance (PDR). An dipole overview about studies of the PDR is Be window accelerator steerer given in Ref. [6]. Most of the experi- electron- hall beam dump ments with bremsstrahlung at gELBE radiator have focused on the investigation of dipole quartz window dipole strength in the energy region of beam Pb hardener the PDR and the spin-flip resonance collimator up to the neutron threshold.

Pb Photon-Scattering Experiments HPGe detector at γELBE Photon scattering from nuclei, also called nuclear resonance fluorescence (NRF), is a suitable tool to study the target photoabsorption cross-section and Pb the related dipole strength function photon- PE experimental beamdump below the neutron threshold. NRF ex- cave periments at gELBE enable the study of photoabsorption cross-sections in 1 m a wide energy range, even up to the highest neutron-separation energies that can reach values up to about 15 door MeV for light, neutron-deficient nuclei. However, two complications, often neglected in NRF experiments at Figure 2. The bremsstrahlung facility γELBE and the experimental cave. lower energy in the past, become very important for the excitation of nuclei system. At high excitation energy and able in (g,n) experiments. The shape up to high excitation energy. First, the high level density, statistical models of the GDR has been phenomenologi- level density can be very high and a are applied to describe reaction rates, cally described by a standard Lorentz considerable number of transitions is which use g-ray strength functions to function or an extended expression in- not resolved but forms a quasicon- describe the average transition proba- cluding terms taking into account nu- tinuum in the measured spectrum and bilities in a certain range of excitation clear temperature [3]. Double humps second, a nuclear state can deexcite energy. The experimental determina- or a widening of the GDR caused by to low-lying excited states (inelastic tion and the theoretical understand- quadrupole and triaxial deformation scattering) in addition to the ground ing of the properties of g-ray strength are reproduced with combinations of state (elastic scattering). This means functions has attracted increasing two or three Lorentz functions [4]. In that (a) the intensity in the quasicon- interest because of their importance addition, the magnetic dipole (M1) ab- tinuum has to be included in the analy- for the accurate description of photo- sorption has been taken into account sis and (b) the branching ratios of the nuclear reactions and the inverse radi- by two Lorentz functions, which de- ground-state transitions have to be es- ative-capture reactions, which play a scribe the scissors mode appearing in timated. central role in the synthesis of the ele- deformed nuclei around 3 MeV and To determine the intensity in the ments in various stellar environments. the spin-flip mode appearing around 8 nuclear quasicontinuum, the spectrum Above the neutron-separation en- MeV [3, 5]. of g rays scattered from the target in ergy, the dipole strength function and In the excitation-energy range from atomic processes is simulated by using the related photoabsorption cross-sec- about 6 MeV to the neutron threshold, the code GEANT4 [7] and subtracted tion of nuclei in the ground state are enhanced E1 strength on top of the from the response- and efficiency- dominated by the electric dipole (E1) low-energy tail of the GDR has been corrected experimental spectrum. The giant dipole resonance (GDR), observ- observed in various mass regions. contributions of unresolved strength

24 Nuclear Physics News, Vol. 27, No. 4, 2017 facilities and methods

ergy range from about 6 to 10 MeV, which is considered as the PDR [12].

Results and Prospects The NRF experiments at gELBE have improved our knowledge of dipole-strength functions below the neutron-separation energy. Enhanced strength in the PDR region has been studied in several N = 50 isotones and compared with predictions of the quasiparticle-phonon approximation and the quasiparticle-phonon model [12]. A systematic study of the dipole strength in the PDR region of xenon isotopes revealed that the strength increases with the neutron number, whereas the nuclear deformation has a minor influence [11]. An important Figure 3. Detector setup at γELBE. At the left side, the exit of the collimator is issue in all these investigations was seen. The beam travels in the evacuated black plastic tube. The target is mounted the inclusion of strength in the quasi- in the tube and is observed by four HPGe detectors surrounded by BGO escape- continuum of states at high excitation suppression shields. The γ beam is stopped in the beam dump at the right side. energy in the analyses. For this and for the estimate of branching ratios of the ground-state transitions, special statis- to the spectra are demonstrated for The various steps of the analysis tical techniques were developed and the nuclides 139La [8] and 208Pb [9] are shown in Figure 5 for the exam- applied at HZDR [10, 11], which have in Figure 4. It is obvious that there is ple of 86Kr [12]. The photoabsorption meanwhile been adopted by other a considerable amount of intensity in cross-section obtained from the analy- groups. The photoabsorption cross- the nuclear quasicontinuum above the sis just described connects to the (g,n) sections, determined in this way con- atomic background in the spectrum cross-section at the neutron threshold, tinuously up to the neutron threshold, of 139La, which has a high level den- which proves the applied procedures can be combined with (g,n) cross-sec- sity, whereas the atomic background and underlying model assumptions. tions and provide experimental input coincides with the continuum in the Note the enhanced strength in the en- strength functions over a wide energy spectrum of 208Pb, which has a com-

6 6 paratively small level density, and 10 10 thus reduced intensity in the nuclear 139 γ,γ kin 208 kin 5 La( ’) Ee = 11.5 MeV 5 Pb(γ,γ’) Ee = 17 MeV quasicontinuum. 10 10 experimental spectrum 4 4 In the analysis of the spectrum ob- 10 10 tained after subtraction of the atomic 3 3 10 10 experimental spectrum Counts background, simulations of statistical Counts 2 2 10 10 g-ray cascades using the code gDEX atomic background [10, 11] are performed to estimate in- 1 1 10 10 atomic background tensities of branching transitions from 0 0 10 10 high-lying to low-lying excited states. 2345678910 2345678910 The branching ratios of the ground- Eγ (MeV) Eγ (MeV) state transitions obtained in this way Figure 4. Response-corrected experimental spectra (red) measured in the are applied to deduce the photoab- 139La(γ,γ9) (left panel) and 208Pb(γ,γ9) (right panel) experiments at γELBE com- sorption cross-section from the mea- pared with simulated atomic backgrounds (blue), multiplied with efficiency and sured scattering cross-sections. measuring time. Data from Refs. [8,9].

Vol. 27, No. 4, 2017, Nuclear Physics News 25 facilities and methods

25 11. R. Massarczyk et al., Phys. Rev. Lett. 112 (2014) 072501. 86 (γ,n) 12. R. Schwengner et al., Phys. Rev. C 87 20 Kr (2013) 024306. 13. M. Beard, S. Frauendorf, B. Kämpfer, et al., Phys. Rev. C 85 (2012) 065808. 15 14. N. Tsoneva, S. Goriely, H. Lenske, (γ,γ’)corr and R. Schwengner, Phys. Rev. C 91 (mb) γ TLO (2015) 044318. σ 10 15. R. Raut et al., Phys. Rev. Lett. 111 (2013) 112501. 5 (γ,γ’) 16. H. R. Weller et al., Prog. Part. Nucl. Sn Phys. 62 (2009) 257.

(γ,γ’)peaks 0 45678910 11 12

Ex (MeV) Figure 5. Cross-section data for 86Kr in different steps of the analysis. Black tri- angles: scattering cross-sections in energy bins of 0.2 MeV deduced from intensities of resolved paks. Blue squares: scattering cross-sections σγγ including the intensity in the quasicontinuum. Red circles: photoabsorption cross-sections σγ corrected for the branching ratios b0 of the ground-state transitions (σγ = σγγ/b0) [12]. Green diamonds: (γ,n) cross-sections [15].

RONALD SCHWENGNER range for the calculation of reaction 2. M. Butterling, W. Anwand, T. E. Institute of Radiation Physics, rates in statistical codes [13, 14]. In Cowan, et al., Nucl. Instr. Meth. B 269 Helmholtz-Zentrum particular, neutron-capture rates ob- (2011) 2623. 3. R. Capote et al., Nucl. Data Sheets Dresden-Rossendorf tained in this way are used to describe 110 (2009) 3107. processes of the nucleosynthesis [15]. 4. A. R. Junghans, G. Rusev, R. g Currently, the ELBE facility is also Schwengner, A. Wagner, et al., Phys. used by several external groups for Lett. B 670 (2008) 200. experiments using photon scattering. 5. K. Heyde, P. von Neumann-Cosel, The data gained from the experiments and A. Richter, Rev. Mod. Phys. 82 with broad-band bremsstrahlung are (2010) 2365. often combined with those from ex- 6. D. Savran, T. Aumann, and A. Zilges, periments at the quasimonoenergetic Prog. Part. Nucl. Phys. 70 (2013) 210. and polarized g-ray source HIgS [16], 7. S. Agostinelli et al., Nucl. Instr. Meth. which allow a distinction between E1 A 506 (2003) 250. 8. A. Makinaga et al., Phys. Rev. C 82 and M1 transitions. ANDREAS WAGNER (2010) 024314. Institute of Radiation Physics, 9. R. Schwengner et al., Phys. Rev. C 81 Helmholtz-Zentrum References (2010) 054315. 1. R. Schwengner et al., Nucl. Instr. 10. R. Massarczyk et al., Phys. Rev. C 86 Dresden-Rossendorf Meth . A 555 (2005) 211. (2012) 014319.

Send information on your future events to [email protected]

26 Nuclear Physics News, Vol. 27, No. 4, 2017 meeting reports

The International Conference on Isospin, Structure, Reactions, and Energy of Symmetry: Istros 2017

Istros 2017, the third edition of the international conference on Iso- spin, STructure, Reactions and energy Of Symmetry, was held in Častá- Papiernička, Slovakia on 14–19 May 2017. This biennial conference is organized by the Institute of Physics of the Slovak Academy of Sciences in Bratislava. It was the ancient name of the Danube river, Istros, which served as an inspiration for the name of the conference. The conference aims at providing a platform for a meeting of international and Slovak scientists active in the field of nuclear physics, specifically deal- Figure 1. Group photo of the conference attendees. ing with experimental and theoretical aspects of physics of exotic nuclei and critical point by the beam energy scan and superheavy nuclei. Recent results states of nuclear matter. The organiz- program at RHIC, looking for chiral were presented of production of new ers keep the number of participants magnetic effects as well as observa- flerovium isotopes at Dubna. Decay low, which allows long talks to be tion of the Lambda polarization and spectroscopy of transfermium nuclei given and also to reserve plenty of the measurement of antimatter inter- was discussed in several talks, along time for informal discussions. action. In a further presentation during with the results from studies of spon- Over 50 scientists from 17 coun- the workshop, beam energy scaling of taneous fission. Production of heavy tries from five continents participated charged particle multiplicity was sug- and superheavy nuclei via multi-nu- in the conference (Figure 1). The sci- gested as a possible signature of phase cleon transfer was a topic of several entific program included more than transition in ultra-relativistic nucleus– theoretical and experimental presenta- 40 oral presentations. The confer- nucleus collisions. tions. Also the influence of the nuclear ence started with a session devoted Another widely discussed topic, re- equation of state on fusion hindrance, to the investigations of the nuclear lated to the equation of state, was the preventing the production of heavy equation of state in ultra-relativistic density dependence of symmetry en- nuclei, was discussed. nucleus–nucleus collisions. Recent ergy and its influence on astrophysical Experiments with radioactive results from the ALICE collaboration processes and cosmology. In particu- beams at the new generation of nu- (LHC) were presented, in particular lar, possible negative symmetry en- clear physics facilities were discussed on observed strangeness enhance- ergy at high densities was discussed, in several presentations. Modern de- ment in p+Pb reactions, as well as on along with EoS-gravity degeneracy tectors such as active targets and the the search for chiral magnetic effects. and resulting possibilities for modi- SAMURAI facility were described Other topics covered by presentations fied gravity and new bosonic particles and results on the study of exotic from ALICE collaboration were pro- representing fifth force. nuclei close to the dripline were pre- duction of light nuclei and anti-nuclei Modern theoretical methods for sented. and particle femtoscopy, specifically determination of symmetry energy in Investigations on production mech- baryon correlations and first results finite nuclei and of equation of state anism of intermediate mass fragments for kaon correlations. The presented of neutron matter were also discussed. in nucleus–nucleus collisions and on results from the STAR collaboration Several presentations focused on influence of isospin degree of free- highlighted the search for the QCD production and properties of heavy dom, performed using the CHIMERA

Vol. 27, No. 4, 2017, Nuclear Physics News 27 meeting reports

array, were presented. An interesting Nuclear triaxiality as a next challenge The recently commissioned 2 MV presentation was given also on statis- for the Coulomb excitation technique Tandetron, which is operational at the tical production of hypernuclei. was discussed. Institute of Physics, Slovak Academy Statistical production of light nu- One session was dedicated to the of Sciences in town of Piešťany (Slo- clei such as carbon or oxygen was also ISOLDE facility. General overview vakia), was presented. The scientifi c a topic of presentation, focusing on that involved the recently commis- program of the new laboratory is fo- possible medical applications. sioned HIE-ISOLDE upgrade (post cused on nuclear structure studies and Several sections addressed prob- accelerator of radioacitive-ion beams) on stellar nucleosynthesis reactions. lems related to nuclear structure phys- was given. The laser spin polariza- The venue offered many oppor- ics. It was shown that the concept of tion, β-NMR spectroscopy, and laser tunities for animated scientifi c dis- deformation-driving orbitals, where spectroscopy of negative ions, which cussions, both indoors and outdoors. its manifestation should be most pro- are techniques used at ISOLDE, were Social program included a wine tast- nounced, is not supported by existing discussed. ing at the winery school in the nearby data. The belief that nuclear moments Recent results on the nuclear struc- city of Modra. The conference dinner of inertia depend on pairing corre- ture of seaborgium, rutherfordium, presented to the participants Slovak lations is not supported by existing and nobelium isotopes were presented. national cuisine and wines. Excellent data. The status of understanding of Underground nuclear astrophysics weather allowed participants to enjoy the structure of odd-Au isotopes was was presented, which is pursued by walks and bicycle rides in the sur- presented. the LUNA collaboration in the Gran rounding outdoors of the Little Car- Results on single nucleon transfer Sasso laboratory. The 400 kV cur- pathian hills in Bratislava’s hinterland. reactions on 198,200Hg isotopes yield- rent LUNA accelerator and the unique Also, the sport facilities at the venue ing important information on the sin- low-background conditions of the such as a swimming pool and squash gle-particle nature of 199Hg isotope, underground LNGS laboratory have were available for the participants. which provides the most stringent been and still are the perfect blend for The conference was supported by limit on an atomic electric dipole mo- the study of most of the proton-cap- the Ministry of Education, Science, ment to date. ture reactions involved in the stellar Research and Sport of the Slovak Re- Coulomb excitation technique for H burning. On the other hand, a beam public, by the Slovak Physical Soci- studies of phenomena such as shape of higher energy is required to extend ety, and by the Slovak Research and coexistence and evolution of collectiv- these studies to reactions between Development Agency under Contract ity was presented in great detail. It was heavier isotopes, as those operating No. APVV-15- 0225. shown that Coulex experiments bring during more advanced phases of stel- rich and precise nuclear structure data lar evolution, namely the He and the that can be interpreted in terms of de- C burnings. The LUNA MV project MARTIN VESELSKY formation parameters but at the mo- has been developed to overcome such AND MARTIN VENHART ment only very favorable cases stud- a limit with the new 3.5 MV single- Slovak Academy of Sciences ied with radioactive-ion beam attain ended accelerator to be installed in quality of stable beam experiments. Gran Sasso in summer 2018.

www.nupecc.org

The Nuclear Physics European Collaboration Committee is an Expert Committee of the European Science Foundation

28 Nuclear Physics News, Vol. 27, No. 4, 2017

:: Site maintenance by Gabriele-Elisabeth Körner. Design by Dan Protopopescu (2009) In the same spirit as the earlier editions, NPA8 was the showcase for the most recent developments in the field of nuclear astrophysics covering a wide range of topics from fundamental aspects to instrumentation and astrophysical applications. Room was given not only to the traditional aspects of experimental nuclear astrophysics, such as direct measurements above and underground and indirect approaches, but also to emerging fields such as the measurement of fusion reactions in laser-induced plasmas and of photodissociation reactions. Also significant room has been given to novel experimental techniques that might have important impact on future nuclear astrophysics experiments and on astrophysical modeling and observations, which constitute the necessarymeeting motivations reports and background of the proposed measurements. NPA8: The 8th Nuclear Physics in Astrophysics

International Conference

Figure 1. Group picture from the conference. Figure 1. Group picture. The INFN—Laboratori Nazionali and natural point of view, downtown committee on the basis of recommen- del Sud (LNS) and the Dipartimento Catania and the nearby Mount Etna dations of an international advisory di Fisica e Astronomia of the Uni- are registered in the UNESCO World committee. versity of Catania (DFA) were the Heritage List. In the same spirit as the earlier hosts ofThe the “8thconference Nuclear Physics counted in aboutThe conference,150 participants initiated byfrom the 24editions, countries NPA8 (Figure was the showcase 1) with for 94 Astrophysics” international confer- Nuclear Physics division of the Eu- the most recent developments in the ence (NPA8) that was held from 18– ropean Physical Society, was the suc- field of nuclear astrophysics -cover oral23 Junecontributions 2017 in Catania, and Italy. 24 posterThis cessorpresentations of earlier events with held a broad in Eilat, spectrum ing a wide of rangetopics of topicsin the from field fun -of conference could not have been orga- Israel, in 2001 (but moved to Debre- damental aspects to instrumentation nuclearnized without astrophysics, the support ofincluding several cen,big Hungary) bang nucleosynthesis, and, with a 2-year fre -quiescentand astrophysical stellar applications. burning Roomin the sponsors from the academic arena to quency, in Debrecen (Hungary) (two was given not only to the traditional industrial partners. These are the Is- times), in Frascati (Italy, originally aspects of experimental nuclear astro- maintituto sequenceNazionale di and Fisica in Nucleare,advanced planned evolutionary to be hosted stages, by INFN—Labo novae- andphysics, supernovae such as direct explosions, measurements X - the Dipartimento di Fisica e Astrono- ratori Nazionali del Gran Sasso), Eilat above and underground and indirect raymia bursts,of the University p-, rp of-, Catania,s-, and the r-(Israel),processes, and in Yorkfrom (UK). both the experimental,approaches, but also theoretical to emerging ,fields and European Physical Society, Mesytec, The conference was made up of such as the measurement of fusion re- CAEN, IOP, and EPJ. 16 plenary oral sessions and 1 poster actions in laser-induced plasmas and Catania represented an exception- session. Each oral session was opened of photodissociation reactions. Also ally suited venue. From a scientific by approximately two invited talks. significant room has been given to point of view, Catania hosts one of Invited speakers of the plenary ses- novel experimental techniques that the oldest universities in Europe and sions were selected based on their age, might have important impact on future one of the four national laboratories talent, impact, and with a right bal- nuclear astrophysics experiments and of INFN. From a historic, artistic, ance in gender by a scientific program on astrophysical modeling and obser-

Vol. 27, No. 4, 2017, Nuclear Physics News 29

meeting reports meeting reports

NPA8: The 8th Nuclear Physics in Astrophysics International Conference meeting reports

vations, which constitute the necessary motivations and background of the proposed measurements. The conference counted about 150 participants from 24 countries (Figure 1) with 94 oral contributions and 24 poster presentations with a broad spectrum of topics in the field of nuclear astrophysics. The event was attended by a large number of researchers at the start of their scientific career together with well-established senior scientists. Such a diversity in experience, nation- ality, and research expertise made NPA8 an ideal platform for cross- fertilization between the disciplines, stimulating new ideas and scientific Figure 2. Prof. C. Spitaleri, fifth from the right, on the celebration of his retire- networks. The participation of young Figurement. 2. Prof. C. Spitaleri, fifth from the right, on the celebration of his retirement. Please confirm mention researchers and of scientists from less favored countries was possible thanks of each figure in the article or update as needed. to the EPS conference grants and the invited speaker, who presented the announced by N. Colonna, member support from the local organizing recent activity on clustering in nuclei of the EPS Nuclear Physics Division committee, who made available cheap and its connection with the problem of Board, on 21 June. The 9th edition of or free accommodation for many par The- electronINFN— screening.Laboratori Nazionali del Sudthis (LNS) conference and thewill Dipartimentobe held in Frank di- Fisica e ticipants. During NPA8 a special event was furt, Germany, and will be jointly On 19 June the ConferenceAstronomia chair- organized, of the University to celebrate of theCatania scientific (DFA) organized were the byhost Goethes of the University, “8th Nuclear the Physics men, C. Spitaleri and M. Lattuada, achievements of the conference chair- Max-Plack-Institute for Nuclear Phys- inaugurated the meeting. The directorin Astrophysics man, C.” iSpitaleri,nternational on theconference occasion (ofNPA8 ics,) thatthe Technical was held University from 18 –of23 Darm June- 2017 in of the Laboratori Nazionali del Sud his retirement (Figure 2). The ses- stadt, and the GSI. of INFN, G. Cuttone, and the directorCatania, Italysion. wasThis opened conference by the could conference not have beenThe organized Proceedings without of NPA8 the support will be of several of the INFN Section of Catania wel- co-chair, M. Lattuada, and hosted published in Open Access on EPJ Web comed all the participants. sponsors fromnine invitedthe academic speakers arena including to industrial long- partners.of Conferences. These All are contributions the Istituto haveNazionale di The highlights of the scientific part time collaborators of C. Spitaleri and been subjected to peer review prior to of the conference came from variousFisica Nucleare,world-renown the Dipartimento experts in thedi Fisica field eof Astronomiapublication. of the University of Catania, the invited presentations given each ses- nuclear astrophysics, discussing the sion throughout the week by theEuropean most scientificPhysical Society background, Mesyte andc, CAEN, impact IOP of ORCID, and EPJ. talented physicists predominantly his scientific career. M. La Cognata from within the European countries. The poster session on Tuesday, 20 http://orcid.org/0000-0002-1819-4814 The most recent developments, results, June was also very lively and trig- and future perspectives in the different gered many useful discussions among C. Spitaleri and M. Lattuada research areas were presented and dis- the participants. During the poster Department of Physics and cussed creating a lively atmosphere, session, members of the international Astronomy, University of Catania, intriguing researchers outside the field scientific and program committee Italy, and INFN—Laboratori of expertise as well. After the invited evaluated the posters. In particular, the Nazionali del Sud, Catania, Italy talks, sessions were open to experts in poster by G. F. Ciani about the direct the respective fields, providing also measurement of the 13C(α,n)16O reac- M. La Cognata the opportunity for graduate students tion at LUNA was selected. INFN—Laboratori Nazionali del Sud, and young postdocs to present their Finally, the host of the forthcoming Catania, Italy work. In particular, we underscore the “9th Nuclear Physics in Astrophys- participation of C. Bertulani as EPS ics International Conference” was

30 Nuclear Physics News, Vol. 27, No. 4, 2017 meeting reports

Strangeness in Quark Matter

Figure 1. More than 210 participants attended the 2017 meeting of the Strangeness in Quark Matter conference in Utrecht. [Image Credit: Pieter van Dorp van Vliet, Utrecht University].

The 17th edition of the international uted parallel talks, and a poster ses- structure and equation-of-state of conference on Strangeness in Quark sion. Three discussion sessions pro- dense and strange matter, quite similar Matter (SQM 2017) was held from vided scope for the necessary debates to the environment created in relativ- 10–15 July 2017 at Utrecht University on crucial observables to characterize istic heavy-ion collisions. in the Netherlands (http://sqm2017. strongly interacting matter at extreme Representatives from all major nl). The SQM series focuses on new conditions of high baryon density and collaborations at CERN’s Large Had- experimental and theoretical develop- high temperature and to define future ron Collider and Super Proton Syn- ments on the role of strangeness and possible directions. One of the discus- chrotron, Brookhaven’s Relativistic heavy-flavor production in heavy-ion sions centered on hadronic resonance Heavy Ion Collider (RHIC), and the collisions, and in astrophysical phe- production and their vital interactions Heavy Ion Synchrotron SIS at the GSI nomena related to strangeness. This in the partonic and hadronic phase, Helmholtz Centre in Germany made year’s SQM event attracted more than which provide evidence for an ex- special efforts to release new data at 210 participants from 25 countries tended hadronic lifetime even in small this conference. Thanks to the excel- (Figure 1), female researchers mak- collision systems and might affect lent performance of these accelerator ing up 20% of the attendees. A two- other QGP observables. Moreover, facilities, a wealth of new data on the day-long graduate school on the role future astrophysical consequences for production of strangeness and heavy of strangeness in heavy ion collisions SQM following the recent detection quarks in nuclear collisions has be- with 40 young participants preceded of gravitational waves were outlined: come available. the conference. gravitational waves from relativis- Among the highlights presented at The scientific program consisted of tic neutron star collisions can serve the conference, the ALICE collabora- 53 invited plenary talks, 70 contrib- as cosmic messengers for the phase tion reported new results on strange

Vol. 27, No. 4, 2017, Nuclear Physics News 31 meeting reports

and multi-strange hyperon production Experimentally, the field faces high The next edition of the SQM con- in heavy-ion collisions with a colli- prospects for future measurements at ference will take place in Bari, Italy, sion energy of 5.02 TeV per nucleon- the Facility for Antiproton and Ion in June 2019. nucleon pair and the first measurement Research in Darmstadt, NICA at JINR of charm baryons (Lc and Xc) in pro- Dubna, and at CERN (namely detec- ORCID ton–proton and proton-lead collisions tor upgrades at the LHC during long André Mischke at the LHC. Furthermore, ALICE shutdown 2 and the AFTER program). http://orcid.org/0000-0003-0078-4522 performed the most precise measure- On the theory side, new development of the hypertriton lifetime, an ments and vigorous research efforts André Mischke exotic nucleus composed of a proton, are taking place toward a full under- Utrecht University, a neutron, and a lambda particle. The standing of strangeness production The Netherlands CMS collaboration reported progress and open heavy-flavor dynamics in in understanding the different energy heavy-ion collisions. Global polariza- losses for charm and beauty quarks in tion in heavy-ion collisions is also a Note the hot QCD medium, while the STAR current topic of interest since it allows Published with license by Taylor & Francis experiment at RHIC gave an update the study of the vorticity of the me- © André Mischke on global lambda polarization, which dium and the initial magnetic field. This is an Open Access article distributed under the terms of the Creative Commons reveals that the curl of the fluid cre- Four young scientist prizes, spon- Attribution License (http://creativecom ated at RHIC is much higher than that sored by the European Physical Jour- mons.org/licenses/by-nc-nd/4.0), which in any fluid ever observed. Enhanced nal A, were awarded to the best par- permits unrestricted use, distribution, and strangeness production in small sys- allel talk and poster presenters: Heidi reproduction in any medium, provided the tems, as reported by the HADES, Schuldes (Goethe University Frank- original work is properly cited. The moral rights of the named author(s) have been as- NA61/SHINE, and ALICE collabora- furt, Germany), Christian Bierlich serted. tions, has also reignited the discussion (Lund University, Sweden), Yingru Xu surrounding strangeness production as (Duke University, USA), and Vojtech a signature of the quark-gluon plasma. Pacik (Niels Bohr Institute, Denmark).

READ LEARN DISCUSS PARTICIPATE

32 Nuclear Physics News, Vol. 27, No. 4, 2017 news and views

On the Development of Nuclear Physics in Cuba

Introduction and products: the Center of Applied reaching 28% of total nuclear profile Giving an overview of the origins Studies for Nuclear Development students. and development in Cuba of Nuclear (CEADEN) and the Center of Isotopes As to higher education, up to 1980 Physics and related technologies, 37 (CENTIS); a small nuclear university: only 48 professionals had graduated years after the creation of the Cuban the Higher Institute of Nuclear Sci- from nuclear specialties. However, Nuclear Program (PNC) is an arduous ences and Technologies (ISCTN); and up until mid-1992, the total number task, but it is pertinent to briefly ex- four institutions for the higher mid- of graduates in the USSR, Eastern plain how the Cuban nuclear pathway level: three Specialized Pre-university European countries, and Cuba, in was born and developed; the context Institutes in Exact Sciences (IPECE) around 50 specialties, amounted to when the complex infrastructure that and one nuclear polytechnic; and two approximately 1,100. In 1987—start- the PNC demanded was erected, from as support for information and au- ing from the Faculty of Science and the pillars. tomation: the Nuclear Energy Infor- Nuclear Technologies (FCTN) of the In 1976, the construction of a nu- mation Center (CIEN), and the Main University of La Habana, founded clear power plant in Juraguá was part Calculation Center of the SEAN. An- in 1981—was created the ISCTN. of an intergovernmental agreement other major project was the Nuclear This well-equipped university pre- signed with the USSR, which by its Research Center (CIN), which was pares highly qualified professionals significance it was considered “The implemented from the projection and in Nuclear Physics, Radiochemistry, Endeavor of the Century.” construction until 1992, when like the Nuclear Engineering (the specialty To integrate all efforts into a co- CEN-Juraguá, it was interrupted. was called Nuclear Power) and Physi- herent national strategy, with well- A crucial aspect of that period cal Engineering. In 2003, ISCTN was defined objectives and priorities, and should be mentioned briefly: The im- renamed the Higher Institute of Tech- to create a solid infrastructure for the pact of selection and training of hu- nologies and Applied Sciences (IN- development of the nuclear energy, man resources for the PNC. As a result STEC) and incorporated the specialty in January 1980, the Cuban Atomic of an initiative by the SEAN and the of Meteorology. Table 1 shows the re- Energy Commission (CEAC), and Resolution of the Ministry of Educa- sults to date. the Executive Secretariat for Nuclear tion (MINED), in 1980, the three men- As a result of the international Affairs (SEAN) were constituted [1]. tioned IPECE were established for geopolitics and the subsequent world The first was aimed at enforcing the the study of science and engineering crisis, in the early 1990s, the main nu- policy that had been approved to co- in higher education, which were an clear investments were suspended and ordinate and control the efforts of the especially valuable source of excel- the PNC was slowed down. In 1994, national entities involved in nuclear lent graduates for the Nuclear sphere, the Ministry of Science, Technology activity and the SEAN was in charge of implementing the approved policy Table 1. Total number of graduates in nuclear specialties broken down and developing the scientific, techni- according to academic years, specialties, and institutes of higher education. cal, regulatory infrastructure, interna- ISCTN tional ties, and the human capital. 1988/2013 FCTN (/2 of them INTEC Total The Fifteen Decisive Years 1981–87 1988–1992) 2003–2016 graduates (1980–1994) Energy & nuclear tech. 1781 203 /2 101 163 544 In those years [2], the two centers engineering for systems of Radiological Protec- Nuclear physics 32 181 /2 76 156 369 tion and Nuclear Safety: the Center Nuclear physics 0 45 /2 32 0 45 for Radiation Protection and Hygiene engineering (CPHR) and the Nuclear Safety Cen- 2 ter (CSN) were created; two for pro- Radiochemistry 0 121 / 29 125 246 moting basic research applied and the Total 210 550 /2 238 358 1204 dissemination of isotopic techniques 1The specialty was called Nuclear Energy; 2total graduates between 1988–1992.

Vol. 27, No. 4, 2017, Nuclear Physics News 33 news and views

Table 2. AENTA centers, by sector and area of application. Sector Institution Area of application Health CENTIS Production of radiopharmaceuticals and pharmacokinetic studies CEADEN Radiosterilization (tissues, products for medicinal use) Agriculture and industry CEADEN Irradiation technologies (radiometagenesis of plants) INSTEC Gamma and neutron profiling (optimization of industrial processes) Environment CEADEN X-ray fluorescence system (analytic determination of environmental samples) INSTEC Neutron activation analysis and other related analytic techniques (analytic determination of environmental samples) Hydrology CPHR Natural radioactive tracers (dating of samples) INSTEC Tracers/radiotracers and non-radioactive tracer technology (hydrologic and hydrochemical characterization of aquifers) Radiation safety CENTIS Metrology of radiation (measurement of activity) CNSN Nuclear regulatory organ CPHR Radioactive waste management; radioactive decontamination of materials; metrology of radiation (doses); foodstuffs and scrap radiological surveillance Source. Based on Influencia de las aplicaciones en la sociedad contemporánea [15]. and Environment (CITMA) was cre- interaction with radiation, the tools of In order to guarantee the metrol- ated by merging the already existing Theoretical Nuclear Physics are used. ogy, the Radionuclide Metrology Lab- Academy of Sciences (ACC) with Equipment based on interaction with oratory (CENTIS-DMR) at CENTIS SEAN. It also founded its Agency for the substance of different types of ion- and the Secondary Dosimetric Cali- Nuclear Energy and Advanced Tech- izing radiations (neutrons, gamma ra- bration Laboratory (LSCD) at CPHR nologies (AENTA). diation, and beta) have been designed was created. Another service of un- and built for industrial applications in: doubted scientific and social value is Nuclear Technology Applications the nickel industry, sugar industry, and the study of the biological effects of in Cuba the detection of weaknesses in welded ionizing radiations. The use of estima- The scientific and innovation ac- joints in the steel and mechanical tion methods of radiological dosage tivity in the field of Nuclear Physics industry. Within the National Geo- in accidental situations allowed ob- can be grouped into three fundamental logical Prospection Program, was the taining positive results with the chil- areas: applied, theoretical, and experi- prospecting of uranium and thorium, dren and other people affected by the mental research. both in deposits as well as in associa- Chernobyl accident [4]. Among 1990 At present, there are about 160 in- tion with other minerals. Another of and 2012, almost 25 thousand persons stitutions and sectors under different these applications based on the effects from Ukraine, Belarus, and Russia ministries that apply nuclear technolo- of ionizing radiations, in this case on were treated with internationally rec- gies and radioactive sources. Table 2 biological minerals, is the creation ognized results. shows the AENTA’s centers by sectors of improved varieties of several eco- and application areas [3]. nomic crops. The Development of Theoretical The main applications are related The applications in Public Health and Experimental Nuclear Physics to the analytic and nucleonic meth- have been notable and diverse; sig- Scientific activity in the field of Nu- ods used in applied Nuclear Physics: nificant achievements have been made clear Physics from the organizational neutron activation analysis (NAA), in the production and use of radio- approach of the PNC can be divided gamma spectrometry (GS), X-ray flu- pharmaceuticals in nuclear medicine into two stages (Table 3). In the first, orescence (XRF), neutron reflection in general as well as in open source between 1980–1995, the objectives of and moderation, beta backscattering, therapies and the application of scientific programs were defined; the gamma transmission and absorption, closed source radiation therapy for conditions and infrastructures were and the track etching technique. For safe and efficient treatments against created and the head institutions and the mathematical simulation of the cancer. the leading groups were consolidated.

34 Nuclear Physics News, Vol. 27, No. 4, 2017 news and views

Table 3. Scientific activity in the field of nuclear physics. the study of the interaction among The scientific activity in the field of nuclear physics low-energy neutrons in structural materials used in nuclear technology, First stage the development of theoretical meth- 1980—1995 ods to calculate the cross-section in Creation of the priority objectives of scientific programs, the required conditions and the proximity of the reaction thresh- infrastructure. Consolidation of leading institutions and groups. old, and in determining the influence Second stage of anharmonism in the calculation of 1996–2015 cross-sections and neutron angular Reorientation of science programs and innovation activities toward: improvement distributions. Nuclear fission was also of non-energy nuclear applications; other related applications and existing investigated, associated to the low- fundamental studies of greater impact. energy interaction mechanism for the reaction of excited neutrons with the nuclei of the actinides zone. Research done before 1976 [16]. The Atomic Energy, I.V. Kurchatov (IEA) Also using the IBR-30 reactor of second one, from 1996–2015, began theoretical work had been carried out the IUIN of Dubná, experimental in- with the economic restrictions and the using a microscopic approach to the vestigations were carried out, such as tightening of the embargo, forcing the shell model, and investigated the in- the study of the radiation force func- definitive abandonment of the CEN- fluence of input states on the character tion of several strongly deformed Juraguá Project. of the fluctuations in both the neutron transition nuclei and by means of the effective sections and the inelastic reaction (n, g) in isolated resonances First Stage Development [5] dispersion in strongly deformed nu- and the reaction (n, p) by means of Research in Nuclear Physics de- clei [6]. The author of that and other resonant neutrons, which allowed the veloped in two directions (Table 4): research cited here, F. Castro Diaz- determination of the wave function theoretical and experimental. The Balart—based in the school of LD structure of the composite nucleus theoretical research, focused on col- Landau—led the creation of a group states for light nuclei in the 22 < A lection of nuclear data, the study of of qualified researchers in Cuba with < 41 zone. With the cooperation of nuclear fission and reactor physics, led young theorists of outstanding trajec- the IAEA, works aimed at measur- to an increasing domain of basic nu- tory, trained in several foreign univer- ing cross-sections and angular distri- clear theories, together with the use of sities. The works published under the butions of neutron-induced reactions modern models for the calculation of signature of J. R. Fernández Díaz were with energy of 14 MeV were done. reactions. Part of the experimental re- authored by him. search was carried out abroad, due to In the cycle of works [7–9] it can Second Stage Development the lack of appropriate national facili- be seen that the theoretical investiga- It began in 1996 (Table 5) and was ties, where neutron activation, thermal tions up to 5 MeV were focused on focused on the description of atomic neutron reflection, and other nuclear analytical techniques were able to as- Table 4. Development of the first stage. similate. First stage research in nuclear physics In order to develop the first stage in the National Scientific Program, lines Theoretical Experimental of research were determined as: the ● Nuclear data ● Neutron activation prediction, collection and valuation of ● Study of nuclear fission and the physics ● Reflection of thermal neutrons neutron nuclear data from the struc- of reactors ● Other nuclear analytical techniques ture of the nucleus, nuclear reactions, ● Basic nuclear theories and nuclear fission process. ● Modern models for the calculation of A milestone in the development neutron-induced nuclear reactions within of this specialty was the creation of a broad interval of nuclei and energies a group of young scientists of excel- ● Physics-neutron and dynamic calculations lence. It should be noted that, druing of reactors 1977–1980, at the Moscow Institute of

Vol. 27, No. 4, 2017, Nuclear Physics News 35 news and views

nuclei as complex systems; the study Table 5. Development of the second stage. and the generalized description of the Second stage research in nuclear physics excited nuclei and their mechanisms Theoretical Experimental of nuclear relaxation; as well as in the ● Atomic nuclei as complex systems ● Development of nuclear methods of deformed nuclei zone. analysis in several areas of interest Regarding applied and experimen- ● Excited nuclei ● tal Nuclear Physics, projects were as- ● Mechanisms of nuclear relaxation Collection of nuclear data for nuclear techniques sociated with development of nuclear ● The impact of the nuclear structure on ● methods of analysis and also used to heavy ion reactions near the Coulomb Characterization of zeolite and oil model and simulate nuclear and radio- barrier reserves active processes, and to collect nuclear ● ● Violation of parity in nuclear reactions Environmental studies for the sugar data for nuclear techniques and others. near deformed nuclei zone agroindustry Among the results obtained, we can ● Studies on the optimization of the mention the characterization in the medical dosage to be administered sugar agroindustry in environmental ● Research in the field of nuclear studies and on the dosage optimiza- fission reactions tion studies to be administered [10]. ● Works on the high energy physics In the past decade, studies were devel- linked to ALICE experiment on oped in the modeling and simulation (LHC) at CERN of experimental facilities, the level of heavy metals pollution in marine sediments and in urban soils of impor- develop a coherent R&D program of level through thousands of publica- tant cities in the country [11, 12], and nuclear sciences and technologies. tions in renowned journals, obtained the fission of light stable and weakly The magnitude of the CEN-Jura- patents, and the awards granted by the linked exotic nuclei and the influence guá venture also presents a cultural ACC and other national and interna- of break-up process on the fission of balance manifested in the preparation tional institutions. weakly linked nuclei [13]. level, experience, and technological In recent years, young nuclear maturity reached by its professionals, physicists have begun work on High References technicians, and executives of many Energy Physics linked to the ALICE 1. F. Castro Díaz-Balart, Energía Nu- specialties. clear y Desarrollo (La Habana. Ed. experiment of the Large Hadron Col- Nuclear techniques and radioactive Ciencias Sociales, 2da edición 1991, lider (LHC) at CERN. The main resources are currently applied in many por Colihue, Argentina). sults in this line have been obtained institutions from different sectors. 2. F. Castro Díaz-Balart, Nuclear En- and characterized in the Inner Track- There is also an infrastructure that ergy: Environmental Danger or Solu- ing System (ITS) of the ALICE exper- tion for the 21st Century (Ed. Lagos includes applications in agriculture, iment, by the reconstruction of traces S.A., Monterrey, México, 2011) (previ- food, sugar, mining, and industry in produced by radiation beams [14]. ous editions in different languages and general. It is necessary to emphasize countries). the application achievements of the 3. A. Díaz García, 2006. Rev. Nucleus 40 Conclusions public health system, which includes (2006) 6. The experience of the Cuban Nu- services to the biotechnology industry 4. O. García and J. Medina, Nucleus 37 clear Program confirms that a small and preclinical and clinical research (2005) 39. country with limited resources, in ad- on pharmaceuticals. 5. F. Castro Díaz-Balart, Nucleus 7 dition to the appropriate transfer of Finally, a key factor has been to (1989) 15. 6. J. R. Fernández Díaz and V. K. Sirot- equipment and knowledge from in- count on the valuable cooperation kin, Nucl. Phys. A 312 (1978) 17. dustrialized nations, can only hope to with international nuclear research 7. J. R. Fernández Díaz and R. Cabezas implement a nuclear energy peaceful centers and the IAEA. Nuclear Phys- Solórzano, J. Phys. G 9 (1983) 1115. program if it is able to create the nec- ics has also provided greater visibility 8. J. R. Fernández Díaz and Cabezas essary infrastructure, train staff, and for Cuban science at the international Solórzano, 1986. Proc. Int. Cont. on

36 Nuclear Physics News, Vol. 27, No. 4, 2017 news and views

Nuclear Physics, (Harrogate, United 13. P. Silveira Gomes et al., Physical Re- Kingdom VI, 1986), 421. view C: Nuclear Physics 71 (2005) 9. J. R. Fernández Díaz, R. Cabezas 017602. Solórzano, and R. López Méndez, Yad 14. K. Aamodt et al. Eur Phys J. C 71 Fyz. 41 (1985) 1508. (2010) 1655. 10. C. A. Sánchez Catases et al. 2003. 15. A. Díaz García. Rev. Nucleus 40 Alasbimn Journal 6 (2003) 22. (2006) 6–14. 11. J. T. Zerquera et al., Radiat. Prot. Do- 16. Pérez Rojas et al., Estado actual de las sim. 121 (2006) 168. ciencias físicas en Cuba. In las Cien- 12. O. Díaz Rizo et al. J. Radioanal. Nucl. cias Básicas: Examen preliminar de FIDEL CASTRO DÍAZ-BALART Chem. 292 (2012) 81. su situación actual en Cuba y a nivel Academy of Sciences of Cuba mundial. (1976) 45–46.

www.tandfonline.com

Neutron FEATURING: What Happened at Les Houches in 1954

Volume 28, Issue 3 November/December 2017 • Vol. 30, No. 6 NewsJuly/August/September 2017

IN THIS ISSUE FELs Status: Horace & SpinW workshop at ISIS, UK Neutrons greet Faraday at Warwick A Look Ahead High Brilliance compact accelerator driven sources for Europe to 2018 JDN21017, the French user meeting on the Mediterranean coast

Please contact Maureen Williams for advertising opportunities: [email protected]

Vol. 27, No. 4, 2017, Nuclear Physics News 37 in memoriam

In Memoriam: Arthur Kerman (1929–2017)

the MIT Center for Theoretical Physics and, as a mutual colleague Mike Camp- bell has stated, “The world is a little more empty and quiet without Arthur in it.” His physics spontaneity and enthusiasm is missed at his many regular stops. As Director of the Center, Arthur was incomparable in nurturing a community approach to physics! Arthur’s influence on the community—and on me personally—had many other dimensions as well. As a starting faculty member at MIT, he Arthur Kerman joined the post-Sputnik Physical Sci- ence Study Committee that developed a Arthur Kerman, who joined the and mentoring of young physicists, and radically different way of teaching high Massachusetts Institute of Technology his innate ability to create a sense of school physics compared to the norm at (MIT) physics faculty in 1956 and re- community among physicists of differ- that time. I was one of the many ben- mained a key contributor there for six ent ages and interests. eficiaries, and indeed it was that course decades, passed away in May 2017 at The accompanying photo captures that led to my commitment, and pre- the age of 88. He was a leader in theo- Arthur’s favorite professional activ- sumably that of many others, to physics retical nuclear physics, making signifi- ity, and he spend a lot of time at it: at in college and beyond. And pivoting to cant advances in the understanding of a chalkboard with chalk in hand, cal- the last few years, Arthur was a regu- both nuclear structure and nuclear reac- culating and talking physics with a lar visitor to the Department of Energy tions, while always being grounded in colleague. Indeed, some have alleged when I served as Secretary. He never experimental reality. Specific nuclear that Arthur was not deeply familiar had to announce his visit—the buzz structure contributions included appli- with any other writing instrument! I was sufficient to alert me that he was cation of the Hartree-Fock approach to first saw this when I was visiting Los in the building. Invariably a chance to deformed nuclei and elucidation of the Alamos during the summer of 1972 as connect with him led to some insight Coriolis effect and pairing correlations a freshly minted Ph.D. Arthur was by on what could be done in the laboratory in nuclei, while he advanced nuclear re- then a well-established leader in the complex to advance the physics enter- action theory on issues such as interme- field but nevertheless simply showed prise and the nation’s interest. diate structure and isobar analog states. up in my little office, went to the board, Arthur was dedicated to his fam- He also served as a member of Presi- and started a peer discussion on quasi- ily, wife Enid and five children, who dent Reagan’s science advisory council elastic electron scattering from nuclei, welcomed Arthur’s “physics family” and over many decades as a key advisor a subject that he had heard was part as an extension. They were unfazed by to the Department of Energy and sev- of my doctoral research. Arthur was Arthur’s enthusiastic “theories,” such eral of its national laboratories, mate- supervising an MIT doctoral thesis on as the attractions of pulling a camping rially influencing laboratory directions the topic in anticipation of the research trailer across the country for a visit to from basic research to large nuclear program at the Bates laboratory, a DOE Livermore or buying a distant restau- security facilities. next generation electron accelerator rant, generally proving that theory and Much more will be written about that would soon be completed and op- practice are not the same thing. We join Arthur’s research and advisory roles in erated by MIT. A lively discussion led them in deeply missing Arthur but cel- academia, national labs, and govern- to an outcome that I came to observe ebrating a remarkable life. ment, appropriate to his considerable over the next forty years as typical of reach and influence. However, we also such “Arthur interactions” with an un- Ernest J. Moniz remember Arthur for his infectious en- countable number of colleagues: we Professor Emeritus, MIT, Cambridge, thusiasm and engagement with any and both learned something! My observa- Massachusetts, USA all physics challenges, his support for tion post was an office across the hall in Former U.S. Secretary of Energy

38 Nuclear Physics News, Vol. 27, No. 4, 2017 in memoriam

In Memoriam: Peter Paul (1933–2017)

U.S. Nuclear Science Advisory Com- key role in the establishment of major mittee (NSAC) from 1980–1983. And new scientific projects as member of as head of NSAC from 1989–1992 he the German Wissenschaftsrat’s “work- directed the development of the 1989 ing group for large infrastructures,” NSAC Long Range Plan, with a key where the seeds for the accelerator recommendation that a Relativistic projects XFEL and FAIR were sown. Heavy Ion Collider (RHIC) be the From 2001–2007 he was member of highest priority for new construction the Helmholtz Senate and his advice in the U.S. nuclear physics program. was very important for the implemen- RHIC was completed a decade later tation of these major programs as well and has produced a stream of outstand- as for the restructuring and reorienta- ing and transformational physics re- tion of several Helmholtz Research sults in quark-gluon plasma research. centers. Peter Paul was Chair of the Stony Peter Paul received numerous Peter Paul Brook physics department twice. In awards for this scientific work, among Peter Paul, distinguished nuclear 1992 he became Distinguished Ser- them an A.P. Sloan Fellowship, the physicist and eminent science admin- vice Professor. Fellowship of the American Physi- istrator, passed away in March 2017 at In 1998, Peter Paul was appointed cal Society Fellow and of the British the age of 84. Born in Dresden, Ger- Deputy Director for Science and Institute of Physics, an honorary doc- many, he received his doctoral degree Technology at Brookhaven National toral degree of Moscow State Univer- in nuclear physics from the University Laboratory and served, concurrently, sity and the Order of Merit First Class of Freiburg in 1962. Shortly afterward as Interim Director of the Laboratory (Bundesverdienstkreuz) from the Ger- he moved to Stanford University as from 2001–2003. During his tenure, man Government. In 2002, he was se- Research Associate and became only RHIC began operating, and several lected as Long Island Entrepreneur of a few years later Professor and one of other major projects started. After this the Year and in 2015, he was inducted the founding members of the nuclear time he joined the Stony Brook neu- into the Long Island Technology Hall structure laboratory at Stony Brook trino group and participated actively of Fame. University in 1967. Under his lead- in research within the international One of his crucial contributions ership the team there became one of T2K collaboration. He served the to physics was the curiosity in and the most influential nuclear physics Stony Brook University administra- complete dedication to scientific re- groups in the United States. tion until recently as Associate Vice search with which he inspired many His research interests ranged from President for Brookhaven Affairs and younger members of the community. nuclear structure physics to accelera- had become Distinguished Service His boundless energy and infectious tor physics, heavy ion physics at low and Research Professor Emeritus in enthusiasm to attack new projects are and high energies, and, in his later the spring of 2015. legend. Beyond his profession, Peter years, to neutrino physics and he made Despite his many commitments and Paul had a broad range of interests: He a strong impact everywhere. In partic- duties in the United States Peter Paul loved reading, sailing, traveling, and ular, he made lasting contributions to never lost his connection to Europe music. He will be missed. our understanding of the structure of and, in particular, Germany. He spent giant resonances in nuclei. He also led, extended and fruitful research periods Peter Braun-Munzinger jointly with Gene Sprouse, the design in Heidelberg in 1974, as awardee of EMMI, GSI, Darmstadt, and and construction of the Stony Brook the Senior Humboldt Research Award Physikalisches Institut, Universitaet superconducting linear accelerator for in 1983 at the Max-Planck-Institut Heidelberg, Heidelberg, Germany heavy ions, the first such machine at a für Kernphysik in Heidelberg, and at university laboratory. Giessen University in 1992. His strong Volker Metag, II From the early 1980s on he also be- connections to Germany led to mem- and Johanna Stachel came very influential as a science ad- bership in many advisory boards and Physikalisches Institut, Universitaet ministrator. He was a member of the committees. In particular, he played a Giessen, Giessen, Germany

Vol. 27, No. 4, 2017, Nuclear Physics News 39 in memoriam

In Memoriam: Adriaan van der Woude (1930–2017)

AVF cyclotron and the preparation of Adriaan served the community in its scientific program. During the pe- several ways. He became a member riod 1963–1965, he went on leave to of the NuPECC Board and first Chair Oak Ridge National Laboratory where of the NPN Editorial Board in 1990. he participated in and initiated re- Adriaan recognized the importance search in several subfields of nuclear of outreach. He started (together with and atomic physics research (e.g., K- Jean Vervier) and actively pursued the shell ionization in atomic collisions, PANS initiative. He became Chair- few-body problems, and production man of the Groningen Royal Physical and scattering of polarized protons). Society in 1990. For his achievements In August 1967, he left Groningen he was elected fellow of the American again for Oak Ridge as permanent Physical Society and later decorated staff member working on these di- as Officer in the Order of Orange- Adriaan van der Woude verse topics. Nassau. In 1972, Adriaan returned to the Apart from his many publications Professor Adriaan van der Woude, newly established KVI as a Senior Sci- Adriaan (co-)authored three books: an a renowned nuclear physicist, passed entist taking active part in the devel- extensive monograph on giant reso- away on 20 August 2017. In him we opment of its research programs and nances, a history of KVI, and a popu- lost a kind colleague and excellent helping build an excellent scientific lar science book on radioactivity. mentor, but above all a good friend. In atmosphere. At KVI, his research con- In July 1995, Adriaan retired and tribute to his memory we recount his centrated on Giant Resonance studies, on this occasion the international “Gi- career and achievements. for which he became internationally ant Resonances” Conference was held Adriaan was born on 3 June 1930 known. He also pursued some of his in Groningen to commemorate his in Westerbroek near Groningen where earlier research interests. In particular, many contributions to the field. he did his university studies and near his work on giant resonances, together In his work and contacts, Adriaan to Haren, where he lived most of his with one of us (MNH), allowed the was very easy to get along with. He life. He started his studies in 1948, KVI to play a leading role worldwide appreciated others and was a very finished his M.Sc. equivalent in 1954, and gave his Ph.D. students and post- good listener although he clearly had and completed his Ph.D. under the su- docs the opportunity to perform high- his own opinions. He was collegial pervision of Prof Henk Brinkman in impact research. and friendly, with a high sense of cor- 1960 on the thesis “Construction and Adriaan was appointed professor at rectness and integrity. Colleagues re- operation of betatron and cloud cham- the University of Groningen in 1980 ally enjoyed working with him. He ber,” a research theme quite different and was associate director of KVI for had an inquisitive, proper, and criti- from themes he pursued later in his several years. In that period, he played cal view of things. His colleagues and life. a key role in defining the KVI’s future many students will fondly remember Following his Ph.D., Adriaan con- plans. He facilitated the collaboration him. tinued working in Brinkman’s group with IPN-Orsay to build the super- at the Physics Laboratory. He was at conducting AGOR-cyclotron, which Sytze Brandenburg, the start of the plans to establish the has been operational since 1996. Dur- Muhsin N. Harakeh, KVI, proposed by Brinkman and his ing the construction period, he led the and Rolf H. Siemssen group. During the period 1961–1967, project, together with Sydney Galès, KVI-CART, University of Groningen, Adriaan was strongly involved in the and spent a sabbatical year in Orsay Groningen, The Netherlands planning and acquisition of the Philips for that purpose.

40 Nuclear Physics News, Vol. 27, No. 4, 2017 calendar

2018 May 22–25 July 1–6 Padova, Italy. 9th International Caen, France. SHIM - ICACS February 1–2 workshop on Quantum Phase Tran- 2018 Pisa, Italy. Probing fundamental sitions in Nuclei and Many-Body http://www.shim-icacs2018.org/ symmetries and interactions by low Systems energy excitations with SPES-RIBs https://agenda.infn.it/ July 9–13 https://agenda.infn.it/ conferenceDisplay. Caen, France. FB22 - XXII Inter- conferenceDisplay. py?confId=13348 national Conference on Few-Body py?confId=13891 Problems in Physics May 27–June 1 https://fb22-caen.sciencesconf.org/ February 19–25 Giens, France. EURORIB 2018 Bormio, Italy. BORMIO-2018: - European Radioactive Ion Beam August 5–10 The IV Topical Workshop on Mod- Conference East Lansing, MI, USA. Nuclear ern Aspects in Nuclear Structure https://eurorib2018.sciencesconf. Structure 2018 https://sites.google.com/site/ org/ https://indico.fnal.gov/ wsbormiomi2018/ conferenceDisplay. June 4–8 py?confId=15187 February 26–March 2 Matsue, Japan. 10th Interna- GSI Darmstadt, Germany. NU- tional Conference on Direct Reac- August 11–17 STAR Annual Meeting 2018 tions with Exotic Beams (DREB) Grapevine, TX, USA. CAARI https://indico.gsi.de/ 2018 2018 conferenceDisplay. http://indico2.riken.jp/ http://www.caari.com/ py?confId=5843 indico/conferenceDisplay. August 26–September 2 March 13–15 py?confId=2536 Zakopane, Poland. Zakopane GSI Darmstadt, Germany. June 7–12 Conference on Nuclear Physics 2018 NARRS2018 - Nuclear Astrophysics Kraków, Poland. MESON2018 “Extremes of the Nuclear Land- at Rings and Recoil Separators 15th International Workshop on scape” http://exp-astro.physik.uni- Meson Physics http://zakopane2018.ifj.edu.pl/ frankfurt.de/meetings/narrs/ http://meson.if.uj.edu.pl/ September 2–7 April 17–20 June 11–14 Bologna, Italy. EUNPC 2018 Groningen, The Netherlands. Ann Arbor, MI, USA. SORMA http://www.eunpc2018.infn.it/ ENSAR2 Town Meeting 2018 September 10–15 http://www.ensarfp7.eu/ http://rma-symposium.engin. Petrozavodsk, Russia. IX Inter- May 13–18 umich.edu/ national Symposium on Exotic Nu- Marianske Lazne, Czech Repub- June 11–15 clei, EXON-2018 lic. RadChem 2018 – 18th Radio- Aachen, Germany. 7th Interna- http://exon2018.jinr.ru/ chemical Conference tional Symposium on Symmetries in September 16–21 http://www.radchem.cz/ Subatomic Physics (SSP 2018) CERN Geneva, Switzerland. May 22–25 hhttps://indico.cern.ch/ EMIS2018 Catania, Italy. IWM-EC 2018 event/651952/ https://indico.cern.ch/ International Workshop on Multi June 18–22 event/616127/ facets of Equation of state and Clus- Ohrid, Macedonia. Sixth Inter- November 13–17 tering national Conference on Radiation Tsukuba, Japan. 8th Interna- http://www.ct.infn.it/iwm-ec2018 and Applications in Various Fields tional Conference on Quarks and of Research (RAD 2018) Nuclear Physics http://www.rad-conference.org/ http://www-conf.kek.jp/qnp2018/ June 24–29 Brasov, Romania. Nuclear Pho- tonics 2018 http://nuclearphotonics2018. eli-np.ro

More information available in the Calendar of Events on the NuPECC website: http://www.nupecc.org/

Subscribe now to receive every issue.

Please photocopy this form and mail to:

Taylor & Francis - Nuclear Physics News Subscriptions 530 Walnut Street, Suite 850 Philadelphia, PA 19106 USA

Tel: +1 215 625 8900 Fax: +1 215 207 0050 ☐ Nuclear Physics News: ISSN 1050-6896 Quarterly, Volume 27 (2017€ )

☐ € ☐ Institutional Subscription (print + online) - £737/ 975/$1223 Personal Subscription - £88/ 120/$146 Complimentary Subscription for nuclear physicists from contributing countries☐ ☐ ☐ Please print: BILL TO/SHIP TO: CHARGE: VISA MC AMEX

Name______Card#______Institution______Exp. Date______Address______Signature______Required for credit card purchase.______Telephone______

City______P.O. #______State______Date______Zip/Post______Country______☐ Make checks payable to Taylor & Francis in US funds only. E-mail______CHECK OR MONEY ORDER ENCLOSED