Advanced Light Source : : Facility Report : : 2007

PUBLISHED BY THE ADVANCED LIGHT SOURCE COMMUNICATIONS GROUP

The ALS Graphene Scene Although derived from What’s graphite, the form of car- Like an “unrolled” car- layer of carbon atoms bon in pencils, these two- Inside: bon nanotube, graphene is arranged in a hexagonal dimensional graphene a densely packed single pattern like a honeycomb. sheets may hold the prom- ise of a new generation of faster, smaller, cheaper, and 2 more durable computer SCIENCE ROUNDUP chips than today's silicon- A selection of ten ALS based devices. Conse- research highlights published quently, interest in the elec- in 2007 tronic properties of this form of carbon has surged worldwide. At the ALS, two 5 research groups, led by AROUND THE RING Alessandra Lanzara of UC Scientific and technical Berkeley and Eli Rotenberg reports from ALS staff and of the ALS, continue to be user groups very active in this field. In 2007, the groups separately published two high-profile 11 papers exploring graphene's PEOPLE AND EVENTS fundamentally interesting BES review, UEC update, and potentially valuable high-profile visitors, awards, The atomic arrangement of graphene (background) is a properties. new faces, etc. honeycomb lattice of carbon atoms arranged in a two-di- Before graphene can be mensional plane. Its electronic band structure consists of engineered into transistors two bands (yellow) that intersect only at a few points at or other electronic devices, 16 the corners of a hexagonal Brillouin zone (red). continued on page 4 FACILITY UPDATES Beam delivery, user demo- graphics, construction proj- Top-Off Gets a Boost mately every minute to re- ects, and new initiatives plenish lost electrons, as The ALS took a big step aspects, culminating in a opposed to every eight towards the successful successful outside review hours, doubling the average completion of the top-off of the radiation safety track- beam current, allowing a upgrade late in 2007. The ing studies and controls. reduction in vertical beam recommissioning of the in- The transition to top-off size, and eliminating the jector complex was suc- mode is motivated by the large swings in temperature cessfully completed and possibility of increasing that can adversely affect user operation was moved brightness and improving storage-ring and beamline from injection at 1.5 GeV to thermal stability, keeping components. The plan is full-energy injection at 1.9 the ALS competitive with before the end of 2008 to GeV. Furthermore, there newer light sources for the operate with top-off injec- was further steady progress next decade. In top-off tion at 500 mA, which will over the last year in studying mode, beam is injected into result in brightness gains all relevant radiation safety the storage ring approxi- continued on page 19 2

Science Roundup

Breaking H2 Symmetry gether) skews the distribution by that coherence-driven transitions Pt/C catalysts used in existing Martín et al., Science 315, 629 breaking the molecular symmetry. are a generic controlling factor PEM fuel cells. This new varia- (2007) for novel quantum phenomena in tion of the platinum–nickel alloy http://www-als.lbl.gov/als/science/ Coherently Condensing doped transition-metal oxides. is the most active oxygen-reduc- sci_archive/150symmetry-break.html Polarons ing catalyst ever reported. A single hydrogen (or deuterium) Mannella et al., Phys. Rev. B 76, Pt3 Revs Up Fuel Cells molecule consists of only two pro- 233102 (2007) Stamenkovic et al., Science 315, Detangling DNA tons (deuterons) and two elec- http://www-als.lbl.gov/als/science/ 493 (2007) Dong and Berger, Nature 450, trons and is perfectly symmetric. sci_archive/169manganites.html http://www-als.lbl.gov/als/science/ 1201 (2007) Linearly polarized photons are Novel quantum phenomena, such sci_archive/139cathode.html http://www-als.lbl.gov/als/science/ similarly symmetric. So one might as high-temperature supercon- Two out of three of the kinetic sci_archive/160topoII.html think that the angular distribution ductivity (HTSC) and colossal barriers to the practical use of The veil has finally been lifted on an of photoelectrons resulting from magnetoresistance (CMR), arise polymer electrolyte membrane enzyme that is critical to the photoionization of the molecule in certain materials where the in- (PEM) hydrogen fuel cells in au- process of DNA transcription and by the photon accompanied by teractions between electrons are tomobiles have been breached: replication and is a prime target of dissociation into a hydrogen very strong, but the mechanism the impractically high amount of antibacterial and anticancer drugs. atom and a hydrogen ion would driving their appearance remains extra energy needed for the oxi- Researchers at Berkeley Lab and itself be symmetric. However, an a major puzzle. Now, angle-re- dation reduction reaction (ORR) the University of California, Berkeley, international team of researchers solved photoemission findings on the catalyst and the loss of have produced the first three-di- from Germany, Spain, and the from an international team led by catalytic surface areas available mensional structural images of a U.S. has now shown that this researchers from Stanford Uni- for ORR. Using a combination of DNA-bound type II topoisomerase need not be the case. When there versity and the ALS provide the probes and calculations, a group (topo II) that is responsible for are multiple quantum paths for first direct spectroscopic evidence of scientists has demonstrated untangling coiled strands of the the process, interference be- that the transition from insulator that the Pt3Ni(111) alloy is ten chromosome during cell division. tween waves in the coherent su- to metal in CMR manganese ox- times more active for ORR than Preventing topo II from disentan- perposition of electron states ides (manganites) results from the corresponding Pt(111) sur- gling a cell's DNA is fatal to the (which exists when the molecular coherent “polaron condensation.” face and ninety times more active cell, which is why drugs that target fragments are still close to- The new findings also suggest than the current state-of-the-art topo II serve as agents against bac-

0 (eV) F –0.1

Energy, E–E Energy, –0.2 With Ni (gray) in the subsurface Sample plot of electron angular layers, the topmost Pt atoms (yel- distribution for ionization of deu- low) have a modified electronic terium. The molecule axis is indi- 0.3 0.4 structure, which alters different ad- –1 cated by the blue and green circles. Wavevector, k (Å ) sorption properties of Pt. Conse- High-resolution three-dimensional The curves represent theory (solid quently, interaction between OH– crystallography images of the bind- red line), experiment (circles), and ARPES data plots photoelectron ions (blue/white) and the Pt skin is ing and cleavage core of type II fit of the experimental data (dotted intensity variation with energy (rel- weakened, leaving more Pt sites topoisomerase (topo II) as it inter- line). The three-dimensional plots ative to the Fermi level) and momen- active for adsorption of O2 (blue). acts with DNA. are also theoretical results. tum in the nodal direction. Color represents photoelectron intensity.

continued on page 3 3

Read more about these and other science highlights at http://www-als.lbl.gov/als/science/ terial infections and some forms of size the larger diamondoid mole- can be magnetic at room temper- scope XM-1 at the ALS to demon- cancer. This first ever structural cules, but to no avail. This situa- ature, attempts to prove that pure strate that magnetic domain walls image of topo II should help in the tion was finally changed in2003 carbon can be magnetized have in curved permalloy nanowires development of future antibacterial when significant quantities of remained unconvincing. However, can be moved at high speed by and anticancer drugs that are even higher diamondoids were found in using a proton beam and an ad- injecting nanosecond pulses of more effective and carry fewer petroleum by researchers in Mo- vanced x-ray microscope at the spin-polarized currents into the potential side effects. lecular Diamond Technologies. Advanced Light Source, a multi- wires, but the motion is largely Now, scientists from Berkeley Lab, national team of researchers from stochastic. This result will have Diamondoids Display Stanford University,Lawrence Liv- the SSRL, the University of Leipzig, an impact on the current devel- Potential ermore National Laboratory, and and the ALS finally put to rest opment of magnetic storage de- Yang et al., Science 316, 1460 Germany have used photoelec- doubts about the existence of vices in which data is moved (2007) tron spectroscopy at the ALS to magnetic carbon. electronically rather than mechan- http://www-als.lbl.gov/als/science/ reveal an intriguing feature: mono- ically as in computer disk drives. sci_archive/155diamondoids.html chromatized electron emission Pushing the Wall Diamondoids are nanometer-sized from a self-assembled monolayer Meier et al., Phys. Rev. Lett. 98, Nano Gold molecules that feature diamond- of diamondoids. This has caught 187202 (2007) Jadzinsky et al., Science 318, crystal cage structures. Adaman- the attention of people who are http://www-als.lbl.gov/als/science/ 430 (2007) tane, the smallest member in the searching for materials for next- sci_archive/153domainwall.html http://www-als.lbl.gov/als/science/ family, consists of one cage struc- generation electron emitters. The quest to increase both com- sci_archive/164gold.html ture, diamantane two, triamantane puter data-storage density and For the first time, a team of sci- three, tetramantane four, and so Magnetic Carbon the speed at which one can read entists led by Roger Kornberg on. On all of these, the dangling Ohldag et al., Phys. Rev. Lett. and write the information remains has synthesized thiol-covered gold bonds on the outer surfaces are 98, 187204 (2007) unconsummated. One novel con- nanoparticles and, using ALS terminated by hydrogen atoms. http://www-als.lbl.gov/als/science/ cept is based on the use of a local Beamlines 5.0.2 and 8.2.2 and SSRL Because of their potential to pos- ci_archive/147carbon.html electric current to push magnetic Beamlines 11-1 and 11-3, conclu- sess novel properties of both dia- Although it has long been sus- domain walls along a thin nanowire. sively ascertained their atomic mond and nanomaterial, intensive pected that carbon belongs on A German, Korean, Berkeley Lab structure (at 1.1 Å resolution). The efforts have been made to synthe- the short list of materials that team has used the x-ray micro- gold–thiol nanoparticle consists

Contact Pads

DW e–

Ferromagnetic Ring

Hext Tetramantane (inset) consists of X-ray crystal structure determination four diamond cages fused together A magnetic domain wall (DW) is of the Au102(p-MBA)44 nanoparticle. and terminated with hydrogen. created between contact pads in a After being functionalized by the permalloy ring 20 nm thick and 1000 replacement of one of the hydrogen A carbon film is hit by a high-en- nm wide by applying and releasing atoms by a thiol group (yellow tip), ergy proton beam, creating a ring- an external magnetic field (Hext). A the molecules will self-assemble shaped magnetic pattern that can fast electronic pulser then launches into large-area monolayers on be imaged with a magnetic-force short 1-ns current pulses with a metal surfaces (purple). microscope. The x-ray microscope current density < 1012 A/m2 into the can then be used to “scan” the ferromagnetic wire. sample for magnetism associated with other elements. continued on page 18 4

have similar energy scales, ARPES can only be explained by elec- Graphene continued from page 1 measurements are crucial to de- tron scattering from collective termining which scattering modes, including a strong elec- an energy gap must be intro- graphene layers, the team found events are most important. tron–plasmon interaction. duced into graphene's elec- that the size of the energy gap At ALS Beamline 7.0.1, the Understanding these inter- tronic band structure. While decreased with thickness and all Rotenberg group succeeded in actions is not just an academic there are several promising ef- but disappeared at four layers. making the first ARPES meas- exercise; it is important because forts underway to induce such a Next on the group's agenda are urement of electron lifetime in although various forms of carbon gap, by adding impurities (dop- finding ways to control the width graphene over a wide energy are known to be superconduct- ing) or fabricating geometrically of the band gap, perhaps by using scale [Bostwick et al., Nature ing, the mechanisms are still confined structures with one or a different substrate material Physics 3, 36 (2007)]. In the ab- unclear. Furthermore, since more dimensions measured in with a different graphene–sub- sence of scattering, the ARPES plasmons can also couple to light, nanometers, the Lanzara group strate interaction strength, and energy band of a single layer of the demonstration of strong has demonstrated that growing to lower the Fermi energy from the graphene would be smooth. electron–plasmon coupling shows graphene epitaxially on a silicon conduction band into the band However, the data clearly showed that novel carbon-based devices carbide substrate so that the gap to allow transistor action. kinks in the band's shape and with both electronic and photonic atoms on each side of the inter- On a more fundamental level, variations in its sharpness that functions might be possible. face maintain their registry could graphene is an ideal playground be a more reliable approach for for exploring “quasiparticle” in- generating a band gap [Zhou et al., teractions in a solid system. Nature Materials 6, 770 (2007)]. Electrons in solids hardly travel Working at ALS Beamlines independently but rather inter- 12.0.1 and 7.0.1, the group used act with a sea of many quasi- angle-resolved photoemission particles—collective excitations spectroscopy (ARPES) to inves- that are responsible for exotic tigate the electronic structure phenomena such as supercon- of epitaxial graphene. The meas- ductivity. While other materials urements yielded a map of the have shown signatures of elec- band structure (energy vs. mo- trons interacting with phonons mentum) with a sizable energy (vibrational excitations) or mag- gap of 0.26 eV. However, the nons (magnetic excitations), the Fermi energy (maximum en- electrons in graphene show clear ergy occupied by electrons) was signatures of scattering from well into the conduction band, phonons, plasmons (collective above where it would be for a oscillations of the electron “gas”), normal semiconductor. and electron–hole pairs over a Aaron Bostwick and Taisuke Ohta at ALS Beamline 7.0.1. In additional experiments much wider energy scale than with increasing numbers of usual. Because the interactions

Shuyun Zhou, Alexei Fedorov, and Alessandra Lanzara at ALS Eli Rotenberg at ALS Beamline 7.0.1. Beamline 12.0.1. 5

THE RING AROUND THE RINGAROUND THE RING Experimental Systems Group: Focus on Optics by Howard Padmore

Some of the most exciting cuss the issues. The workshop frontiers in materials science helped confirm our multi- occur at the nanoscale, where pronged strategy: pushing ex self-organization in energy, situ optical lab-based measure- space, and time often lead to ments as far as possible while complex material properties. developing in situ measurement Soft x-ray light has the right tools within beamlines. wavelength to access the rele- At the ALS Optical Metrol- vant spatial scale and core lev- ogy Laboratory (OML), led by els of the most important ele- Valeriy Yashchuk, we collabo- ments. Combined with rate internationally on next-gen- sophisticated spectroscopic and eration metrology with target The Advanced X-Ray Optics Metrology for Nanofocusing and Co- scattering probes, soft x rays sensitivity and accuracy well herence Preservation workshop at the 2007 ALS Users' Meeting, give us a uniquely powerful tool below the 100-nanoradian level. organized by Kenneth Goldberg and Valeriy Yashchuk. Featuring in modern materials science. Already, the ALS Long-Trace 11 invited talks, the workshop brought together industry represen- The goal of our optics research Profiler II, recently upgraded, tatives and researchers from Japan, Europe, and the US to discuss is to transport, focus, and con- and the new slope-measuring the state of the art and outline the optics requirements of new dition the very high brightness instrument, the Developmental light sources. x-ray sources we have and to Long-Trace Profiler, have per- utilize them in ways that enable formances of 0.25 microradian new science at the ALS. (rms), comparable to the world's Brightness preservation at best instruments of this type. A the levels needed—close to the universal test mirror calibration diffraction limit—is extremely method under development is difficult. Very small perturba- now our strategic direction for tions from a theoretically per- further improvement toward fect optical surface can lead to 50-nanoradian accuracy. We have catastrophic reductions in per- also developed an original formance. While this is impor- method to calibrate the modu- tant for our current beamlines, lation transfer function of mi- where factors of 10–100 may croscopes. The method is based be lost by use of earlier-genera- on use of binary pseudo-random Fabrication of Sc/Si sliced grating with 270-nm pitch size, first tion and nonoptimum optics, gratings and arrays as surface prototype of a superdense soft x-ray grating suitable for the EUV it's especially important for standards, allowing reliable power photon energy range. new beamlines such as the ul- spectral density data to be ob- trahigh-resolution MERLIN tained for 3D scattering simula- beamline and the proposed tions of the beamline perform- strate with a relatively low sity of ~3700 grooves per mm MAESTRO and COSMIC beam- ance of x-ray optics that are also groove density; the blazed mul- and total number of grooves of lines. In the case of MERLIN, under development at the OML. tilayer grating is then polished ~40,000), the first prototype of surface slope distortions at the An LDRD project, led by to reveal an oblique cut of the a superdense soft x-ray grating. level of 0.2 microradians will Dmitri Voronov, explores a multilayer. The resulting sliced Measurements performed at have noticeable effect, and new highly promising technology for multilayer structure has a po- Beamline 6.3.2 have demon- beamlines drive this value ultrahigh-resolution resonant tential line density of up to strated a high efficiency and down even further, to a range inelastic soft x-ray scattering 100,000 lines per mm. We (in dispersive ability in the 41- to challenging to measure and (RIXS): fabrication of a super- close collaboration with a 49-nm wavelength range. We are manufacture. Because this high-density diffraction grating Ukrainian research team) have working to extend the technology problem is not unique to the for soft x-ray energies. An x-ray succeeded in fabricating and to fabrication of an ultrahigh- ALS, we recently held a work- reflecting multilayer is de- testing a Sc/Si sliced grating with density grating for soft x rays, shop with leading experts to dis- posited on an echellette sub- 270-nm pitch size (groove den- continued on page 6 6

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ESG continued from page 5 Scientific Support Group: State-of-the-Art Instrumentation for World-Class Science

by Eli Rotenberg

MAESTRO, the Microscopic dedicated to nanoARPES: angle- and Electronics Structure Ob- resolved photoemission spec- servatory, is the new facility troscopy with 50-nm probe size. planned to replace the existing A new infrared beamline, photoemission branchlines at dedicated to environmental and Beamline 7.0.1 and features a biological studies with near-in- new dedicated “half” insertion frared light, is now being de- device capable of full polariza- veloped. The new beamline, to tion control above 60 eV and a be situated at Sector 5, will accept new entrance-slitless mono- double the light of the existing chromator capable of 3-meV IR beamline and is expected to resolution from 20 to 100 eV have superior stability. Illustration of FTXH using a URA as a reference object. and extended operation up to The MERLIN beamline, 1000 eV. The new beamline's planned to achieve the ultimate where we anticipate spectro- itations by “phasing” the scat- design effort, together with plans resolution for ARPES at the graph systems of high efficiency tered beam directly with a ref- for decommissioning the exist- ALS, has been designed, and as- and throughput up to 1 keV, for erence beam, usually provided ing beamline, were begun this sembly on the ALS floor has be- resolving powers above 105. by a hole in the object. The dis- year to support an application gun. The beamline features the Zone-plate lenses are the advantage is that the interfer- to DOE to fund a new facility continued on page 9 core component of x-ray imaging ence provided by the reference systems but have a resolution beam is weak. An international, limited by nanolithography and multilab team led by Stefano Vacuum Vacuum Eight-pole electromag- Yok e Chamber Cooling an intrinsic limit set by sample Marchesini has developed a Pole net installed at ALS thickness and the depth of field technique that produces x-ray Coil Beamline 4.0.2 provides of the lens. Within the last ten holograms three orders of mag- magnetic fields of up to years, led by the pioneering work nitude more intense than previ- 0.8 T in arbitrary direc- of Janos Kirz and colleagues, a ously possible. The technique Yok e tions, crucial for the new form of imaging based on is a variant of normal FTXH but Mount study of the XMLD an- scattering a coherent x-ray beam uses a uniformly redundant ar- gular dependence. has become popular because its ray (URA) as the reference ob- resolution is, in principle, lim- ject, greatly increasing bright- ited only by the wavelength of ness at the maximum resolution. the light. Phase information is lost, The Marchesini team has used but can be reconstructed nu- the technique at Beamline 9.0.1 merically, using prior knowledge to record a hologram of a of the area containing the sample. nanofabricated test object at 2.3 This reconstruction can now be nm and images of bacterial cells done relatively routinely, but with a resolution of 45 nm in 15 the use of constraint informa- fs using the FLASH free-elec- tion is experimentally limiting and tron laser. This technique al- nal-to-noise ratio and resolu- resolution to ~15 nm. Diffractive is computationally challenging lows direct inversion of the tion, and provides phase and imaging reconstruction methods for reasonably sized images. scattering patterns to images amplitude contrast information could push the resolution be- Fourier-transform x-ray holo- without any iterations, over- simultaneously. Existing litho- yond the nanofabrication limit graphy (FTXH) avoids these lim- comes the tradeoff between sig- graphic methods could push the to a few nanometers. 7

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Macromolecular Crystallography Improves Brightness, Automation

by Paul Adams

Beamlines 5.0.1, 5.0.2, ment in available flux was and 5.0.3. An upgrade of the x- achieved, now generating 1.5 × ray optical elements in all Sector 1011 photons per second at 12.4 5.0 beamlines was completed keV. In February 2007, the 5.0.1 in early 2007. The performance monochromator was replaced of Beamline 5.0.2 was improved with crystals that improve beam by a factor of 3 to 4 and now focusing and also select x rays surpasses the performance of slightly above the selenium peak the macromolecular superbend in order to enable single-wave- beamlines at the ALS, generating length anomalous diffraction 8 × 1011 photons per second at experiments with selenium-de- Performance of the Sector 5.0 beamlines after the 2007 x-ray 10 keV and 400-mA ring current. rivatized proteins. optics upgrade. This has had a tangible impact Beamlines 8.2.1 and on the ability of users to per- 8.2.2. In early 2007, the Berke- completed the installation of a form experiments. User groups ley Center for Structural Biol- Rigaku ACTOR robotic sample working on membrane protein ogy (BCSB) received a $4.8 mil- automounter on Beamline 8.2.2. systems have been able to solve lion award from the Howard This robot is able to automati- structures that otherwise were Hughes Medical Institute (HHMI) cally transfer user samples from not tractable. Other users work- to upgrade Beamlines 8.2.1 and a liquid nitrogen dewar into the ing with crystals of a large macro- 8.2.2 (which are operated for experimental data collection molecular complex were able HHMI). The upgrades include the area without any manual inter- to collect diffraction images installation of robot equipment vention. This permits users to with 15-second exposures instead for sample mounting, high-pre- operate the beamline without of the 120 seconds required on cision instrumentation for crys- the need to open the experi- other beamlines at the ALS. tal handling, a larger CCD de- mental hutch. In the near fu- Replacement of the M101 tector for data collection, and ture it will be possible for users and M301 mirrors significantly improved x-ray optics to gener- to run their experiment re- improved the performance of the ate a 30-micron beam once the motely after sending the sam- Rigaku ACTOR crystal auto- side-station beamlines (5.0.1 and top-off upgrade is complete. ples to the BCSB staff for load- mounter robot installed on 5.0.3). A 5- to 10-fold improve- In June 2007, BCSB staff ing into the dewar. Beamline 8.2.2.

unique tool for nanoscience, polarization of conduction elec- Imaging, Metrology, and EUV Lithography at CXRO combining high spatial resolu- trons, and magnetic domain tion (15 nm) and temporal reso- structure analysis of nanogran- by Erik Anderson lution (70 ps) with a rich set of ular CoCrPt thin alloy films contrast mechanisms: elemen- confirmed a stochastic behavior tal, chemical, topological, and in the domain nucleation process. The Center for X-Ray Op- fabrication and coating facilities magnetic. Magnetism research Specialized zone plates are tics (CXRO) has made signifi- enables it to provide high-reso- using this microscope is impor- extending imaging capabilities cant progress both scientifically lution diffractive optics, coat- tant to the development of high- at the microscope. Depth of field and technologically in its imaging, ings, and other nanostructures, density and high-speed mag- extension with the cubic zone metrology, and industry-funded for its own activities and for the netic storage media. Time- plate and wavefront coding tech- EUV lithography research pro- support of other ALS activities. resolved x-ray images of the nique, performed at Beamline grams. The leading research The full-field soft x-ray mi- vortex core motion revealed for 6.1.2, provides a method for performed at the Center's nano- croscope at Beamline 6.1.2 is a the first time the degree of spin continued on page 8 8

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CXRO continued from page 7 overcoming the depth-of-field– limited resolution for soft x-ray tomography. Spiral and Zernike zone-plate imaging, demonstrated at the coherent optics Beamline 12.0.2.1, enhances contrast through phase sensitivity. The Micro Exposure Tool (MET) on Beamline 12.0.1.3 pro- vides the world's highest-reso- (a) Magnetic domains in a CoCrPt nanogranular alloy thin film imaged at the Co L3 edge with 15-nm lution EUV printing for resist spatial resolution. Scale bar is 120 nm. (b) SEM image of the spiral zone plate. (c) 22-nm spatial reso- and mask research. Resist inno- lution patterning with a high-sensitivity EUV resist. vations are pushing the envelope of resolution (22-nm half-pitch sensitivity of resists. Fortunately, emulates the optical parameters conductor company researchers lines), sensitivity, and line-edge this reduced the required source of EUV lithography tools and is by finding and classifying mask roughness. Collaborative efforts power, which invoked a collec- dedicated to photolithography defects as small as 20 nm wide at the MET and the metrology tive sigh of relief from the in- mask research. As the highest- and 1 nm tall and by validating Beamline 6.3.2 unraveled a sys- dustry. The EUV zone-plate mi- performing tool of its kind, it the effectiveness of repair and tematic underestimation of the croscope on Beamline 11.3.2 serves a broad group of semi- cleaning strategies.

Molecular Environmental Science Under Realistic Conditions

by Hendrik Bluhm, Mary K. Gilles, Tolek Tyliszczak, and David K. Shuh

Scientific investigations at Investigations include studies of Beamline 11.0.2 are split be- magnetic materials, actinide, at- tween two experimental capa- mospheric and cometary par- bilities: a scanning transmission ticulates, synthesized or natu- x-ray microscope (STXM) and rally occurring nanoparticles, an ambient-pressure photoelec- biofilms, mineral–bacteria sus- tron spectrometer (APPES). pensions, and polymers. Exper- Spectroscopy and microscopy iments on magnetic materials Figure 1. Left: Carbon K-edge NEXAFS spectral components. in the soft x-ray region are ex- probe changes in the magneti- Center: Size and composition of collected particles determined by cellent tools for probing envi- zation vector during exposure STXM: organic particles (OC, green), inorganic particles sur- ronmentally relevant samples to magnetic or spin polarized rounded by annular organic shell (InOC, blue), mixed organic inor- under realistic conditions, i.e., electric fields. This relaxation, ganic elemental carbon particles (ECOC, red) and mixed with water or water vapor pres- reversal, or precession of the mag- inorganic, elemental and organic carbon (InECOC). Right: Number ent at ambient temperature. netization vector is examined in fraction and number size distribution indicate a systematic in- While other microscopies time-resolved experiments (70 ps) crease in number of particles with organic composition as a func- provide exquisite images or ele- and addresses scientific issues tion of distance downwind from central Mexico City (T0) to T1 to mental content, none offers the related to information storage T2. (R.C. Moffet et al., in preparation) chemical specificity of STXM in magnetic materials. The dis- with comparable spatial resolu- covery at the STXM of low-field ism microscopy studies include experiments are uniquely fea- tion. The spatially resolved switching of magnetic vortex naturally occurring materials sible due to the combination of chemical information, with res- cores may lead to a new type of and organic nanomaterials. The the insertion device (EPU) and olutions of 25–35 nm, is unique. magnetic memory. Linear dichro- magnetic and linear dichroism continued on page 10 9

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SSG continued from page 6 chamber featuring an upgraded new capabilities will enhance analyzer: the SES-R3000. This the effectiveness and alleviate first quasiperiodic undulator at At the Electronic Structure analyzer features about 1.8 crowding at one of the most the ALS—designed to minimize Factory endstation, we have times the throughput for a oversubscribed endstations at the contaminating higher har- commissioned a new liquid-he- given resolution, and almost the ALS. monics that plague the existing lium-cooled goniometer, capa- three times the maximum an- The SSG group strives to ARPES experiments—and is ex- ble of temperatures from 11 to gular acceptance, of the previ- create state-of-the-art instru- pected to achieve sub-1-meV 2000 K and compatible with the ous analyzer, and will achieve mentation to enable new sci- resolution for the first time at a previous sample holder design. around five times improved ence. The following selected beamline for condensed matter HARP, the Beamline 12 pho- throughput over the old ana- highlights reflect not only studies at the ALS. Operation toemission endstation, will be lyzer. Together with a recent up- world-class science but illus- is expected in early FY09. completely replaced with a new grade to the x-ray optics, the trate the unique capabilities cre- ated in the ALS by the SSG. The x-ray magnetic linear dichroism (XMLD) spectrum of Chemical Dynamics from Table Salt to Titan eled and accounts for the ob- transition-metal ions in mag- served asymmetry (Wilson et netic materials is a very com- al., Nano Lett. 7, 2014 (2007)]. A plicated function of the relative by Musa Ahmed novel multiplexed time-resolved angles between photon polar- photoionization mass spectrom- ization and crystalline and mag- The Chemical Dynamics reaction kinetics of hydrocarbon eter technique has been em- netic polarization directions, Beamline 9.0.2 provides state-of- radical reactions with relevance ployed to investigate the ioniza- and from this function we can the-art experimental resources to combustion and the atmos- tion behavior of two 1-alkenyl derive rich information about to undertake studies of funda- phere of Titan, and the pho- peroxy radicals, which play key the coupling of spins in mag- mental chemical processes using toionization of dopants in ultra- roles in low-temperature oxida- netic systems. SSG's Elke Aren- VUV radiation. Projects under- cold helium droplets. Of the tion and photo-oxidation of hy- holz, in collaboration with Y. taken at the beamline in 2007 many interesting results ob- drocarbons (Meloni et al., JACS Suzuki's group (UC Berkeley) included chemical reactions on tained, four are of particular in- 129, 14019 (2007)]. An experi- and G. van der Laan (Dares- model particle surfaces reflec- terest: Angle-resolved threshold mental study that provides in- bury), have shown that the full tive of atmospheric aerosols and photoelectron spectra recorded formation about the photoion- double angular dependence of diesel exhaust, molecular growth for size-selected beams of ization energies of small carbon the Ni XLMD in a NiO/Co in- mechanisms relevant to com- sodium chloride nanoparticles clusters was undertaken. Cou- terface can be modeled by two bustion chemistry and astro- (radius = 25–250 nm) exhibit a pled with elaborate electronic functions that depend only the chemistry, details of hydrogen size-dependent asymmetry that structure calculations, insight atomic multiplets involved in bonding and structure of small is inversely proportional to par- was provided into the structure the Ni 2p level probed, together water and alcohol clusters, gas ticle radius. The internal elec- and composition of these with the detailed symmetry of phase microhydration studies of tric field amplitude and the pho- species in a laser-ablated super- the materials [Arenholz et al., DNA bases, flame chemistry of toelectron escape probability sonic molecular beam (Belau et Phys. Rev. Lett. 98, 197201 (2007)]. biofuel surrogates, elementary inside the particles were mod- al., JACS 129, 10229 (2007)]. In fact, these results can be ap- Photodissociation and pho- plied generally to Ni in any sim- toionization experiments sug- ilar cubic environment, even in gest that, in Titan's upper at- situations previously approxi- mosphere, VUV radiation may mated by only one angular play an important role in the function. Consequently, previ- formation of complex organic ous results will have to be reex- molecules through photoioniza- amined to derive a true under-

tion of N2 (Imanaka and Smith, standing of the magnetic states. GRL 34, L02204 (2007)]. A study led by J. Banfield (UC Berkeley) used infrared Photoelectron imaging of size-selected nanoparticles exhibit a spectroscopy as well as other size-dependent asymmetry that is inversely proportional to parti- techniques to analyze dense ag- cle radius. gregates of bacterially formed continued on page 10 10

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SSG continued from page 9 Molecular Environmental Science continued from page 8

proteins can limit dispersal of accessible energy range (130– oxygen, water does wet Cu(111). nanoparticulate metal-bearing 2000 eV) at this beamline. Due The wetting is controlled by the phases, such as the mineral to the minute amounts of mate- presence of OH groups on the products of bioremediation that rial needed for STXM experi- surface, acting as anchors for may otherwise be transported ments (10 fg for a particle), a va- water adsorption. This behavior away from their source by sub- riety of radioactive materials results from the difference in surface fluid flow. This work can be safely studied. the dissociation barrier for the used the high spatial resolution Particulate studies examine two surfaces: Cu(110) < Cu(111). of Beamline 1.4.3 to spectrally differences in the chemical When Cu(111) is partially cov- identify the presence of proteins bonding of a particular element. ered by atomic oxygen, its dis- within these nanoparticles. Atmospheric particles collected sociation barrier is decreased Colloidal nanocrystals (crys- at ground sites, successively dis- and hydroxylation and water talline nanoclusters suspended tant from Mexico City, show an adsorption are observed. in liquid) were analyzed using a increase in the number of par- Experimental capabilities at combination of x-ray absorption ticles containing organic carbon Beamline 11.0.2 are in a con- and emission spectroscopies at (Figure 1). This increased oxi- stant state of improvement. The Beamline 7.0.1 [Liu, et al., Nano dation results from atmospheric endstation area was substan- Letters 7, 1919 (2007)]. Because processing and influences the tially rearranged to provide op- these techniques normally are particles' water solubility and timal space for experiments. conducted on solids in ultrahigh atmospheric lifetime. The Major STXM developments in- Top: Illustration of a colloidal vacuum, application to nanocrys- APPES endstation is excellent cluded improved timing nanocrystal with a cobalt cen- tals in liquid required develop- for probing liquid/vapor and schemes for time-resolved ex- ter surrounded by a ligand layer ment of a new water cell with solid/vapor interfaces at Torr periments, experiments em- made up of molecules of an or- sufficiently thin windows to al- pressures. This is ideal for ex- ploying fluorescence or electron ganic surfactant (oleic acid). low the x rays to be absorbed amining the chemistry of inter- yield detection as well as Bottom: Transmission electron and emitted to the detector. faces, the role of water, and for progress in tomography and the microscope (TEM) image of Special care was taken to pro- probing changes in the inter- development of a mini-STXM. cobalt nanocrystals. Scale bar tect the beamline and the syn- face arising due to chemical re- Improvements related to the = 50 nm. chrotron from accidental vent- actions. Under identical relative APPES endstation include the ing. The principle finding was humidity (5%), water wets development of a separate the ability to discriminate the Cu(110), but not Cu(111) (Fig- droplet train apparatus, new metal sulfide nanoparticles chemical state of Co atoms in ure 2). However, if the Cu(111) material sources, and the addi- [Moreau et al., Science 316, 1600 the interior of clusters from surface is partially covered by tion of new turbopumps. (2007)]. They found that pro- those on their surface. The dis- teins trapped within the tinguishing feature of these nanoparticles may have played atoms is that the surface atoms a key role in the aggregation have a different chemical state process. Sulfate-reducing bacte- due to charge transfer to ligand ria can lower the concentrations molecules that were used to of metals in anoxic waters by functionalize the nanocrystal sequestering metals into surfaces. The technique should nanoparticles. The worry is that find wide application to many these very small particles could future studies, since such func- be highly mobile, redissolving tionalization can be used to tai- quickly if conditions change. lor the properties of new mate- Figure 2. Differences in oxygen bonding between Cu(111) and The results presented in the pa- rials for a variety of needs, Cu(110) surfaces (S. Yamamoto et al., J. Phys. Chem. C 111, 7848 (2007)]. per, however, suggest that mi- including magnetism, electron- crobially derived extracellular ics, and energy collection. 11

PEOPLE AND EVENTS by Roger Falcone

High Praise for the ALS in BES operation, as well as for several ecutive Committee (UEC). They instrument achievements, in- also commented favorably on Triennial Review Report cluding the new EPU Beamline the ALS Strategic Plan and 11.0.1 and the steps taken to- pointed out that the ALS has Pedro Mon- entific staff.” This is high praise ward the PEEM3 microscope; taken the lead in establishing a tano, DOE Ba- indeed, only made possible by superbend Beamline 12.3.2, graduate student and postdoc sic Energy Sci- the contributions of all mem- which extended the energy range support program, vital to devel- ences (BES) bers of the ALS staff and users for white-beam x-ray Laue mi- oping a pipeline for future beam- Scientific User working together. crodiffraction and provided en- line and accelerator scientists. Facilities Division Director, has I would like to share with hanced strain sensitivity; the Other than our well-known sent me a summary of the re- you some of the observations. progress on Beamline 4.0.3 staffing shortages, no major port from the triennial DOE Reviewers noted that the ALS has (MERLIN), including an aperi- shortcomings were identified in BES review of the ALS that was made significant improvements odic undulator for harmonic re- the review. Dr. Montano's letter held last March, and I am ex- for the user community, includ- jection; and the move of the ul- accompanying the report sum- tremely proud of the results. To ing a web-based proposal system trafast program to Sector 6.0, mary concludes by “commend- quote the opening paragraph, described as being transparent which resulted in much im- ing the ALS on continuing its “The ALS scientific output con- and fair. They also commended proved intensity on the high- outstanding scientific output tinues to excel with an excep- ALS Safety Program Manager and low-energy branch lines. and instrument development,” tional percentage of publica- Jim Floyd's collaborative style Finally, reviewers were im- a view I heartily share. tions in the 'high impact' of working with users to imple- pressed by the strong interac- This was a gratifying re- category. This reflects positively ment pragmatic safety measures. tions between the ALS and both view, a testament to our collec- on its world-class beamline ca- There was praise for the the Scientific Advisory Com- tive efforts at the ALS. I thank pabilities and outstanding sci- progress made toward top-off mittee (SAC) and the Users' Ex- everyone for a job well done.

by Hendrik Ohldag, 2008 UEC Chair

Users' Executive Committee Update This has also been a year of hind us. visible changes around the ALS Finally, I want to thank you The ALS Users' for DOE facilities. building. Already last years Users' for your support and help and Executive This has been a truly excit- Meeting featured the ground- would like to ask you to work Committee ing year for the ALS. In March breaking ceremonies for the closely with next year's UEC (UEC) repre- the ALS hosted the triennial fa- User Guest House and the User chair Kenneth Goldberg to en- sents more than cility review by the DOE. The Support Building, and the con- sure that the ALS continues to 2000 scientists review committee was very im- struction work on the guest house be an outstanding facility for worldwide who are using the pressed with the quality of the is making good progress. Un- synchrotron radiation science ALS for their research and it research conducted at ALS and fortunately, the start of con- worldwide. I would also like to has been my pleasure to serve by the level of support that sci- struction for the USB had to be thank Wayne Stolte and Phil as the UEC chair this past year. entists, engineers, technical and delayed due to the budget short- Heimann, the program chairs In order to assist ALS users, that administrative staff provide to fall, but work on the foundation of the 2008 Users' Meeting. To- is you, we interact very closely users in order to facilitate their will begin during the fall shut- gether with the help of Sue Bai- with ALS management, repre- research programs. Congratula- down. In the past, one of our ley and her team at the ALS sent you during external re- tions and a big thanks to every- major concerns was the shortage User Services Office, they put views, and voice your concerns body for a job well done! It will of lab and office space and the together an outstanding pro- to various groups on Capitol require the continued efforts of lack of on-site accommodations gram for the 2008 Users' Meet- Hill. In all of these capacities, all of us to ensure that the ALS during beam time. Thanks to the ing with exciting and informa- the UEC addresses a large vari- will be able to provide top-level efforts of the ALS User Services tive plenary sessions as well as ety of topics and issues, ranging support to its users leading to Office, ALS management, and a list of excellent workshops. from facility access, safety reg- outstanding science in the fu- previous UECs as well as your I wish all of you an enjoy- ulations, user housing, ALS up- ture in the light of dire current continued support, we will soon able, exciting, and productive grades to congressional support and future budget scenarios. be able to put these issues be- future at ALS. 12

PEOPLE AND EVENTS

In Memoriam Daniel Chemla, former director of the ALS and Materials Sciences Divisions and major intellec- NIH Director Visits of crystallographic experiments. tual driver in the establishment of the Molecular As part of his tour, Zerhouni Foundry, died at home on Thursday, March 20, the ALS also inspected the NCXT's 2008, at the age of 67. He had been battling a se- newly constructed soft x-ray mi- ries of health problems since suffering a stroke On March 31, 2007, the Di- croscope. This is the first such four years ago. Despite those difficulties, he con- rector of the National Institutes microscope to be designed and tinued to actively lead his research group until for Health (NIH), Elias Zer- built specifically for biological very recently. houni, visited Berkeley Lab and and biomedical imaging. (The As ALS Division Director, Daniel's ambitious the UC Berkeley campus. As NCXT is an NIH National Cen- 20-year roadmap for the ALS laid the groundwork for new beam- part of his visit, he toured the ter for Research Resources that lines, accelerator upgrades, and expanded scientific programs in ALS with Graham Fleming (for- also receives joint funding from materials sciences, ultrafast science, microscopy, and protein crys- mer Berkeley Lab Deputy Di- the Department of Energy, Of- tallography. During his seven-year tenure at the ALS, the number rector), Roger Falcone (ALS Di- fice of Biological and Environ- of users grew from 659 to over 2000. He stepped down as direc- rector), Paul Adams (Head of mental Research.) tor in 2005. Acknowledging Daniel's extraordinary contributions the Berkeley Center for Struc- Zerhouni, a radiographer to the ALS, current ALS Director Roger Falcone observed, “He was tural Biology), and Carolyn with considerable experience in a visionary and tireless leader. He set the ALS on a path of fron- Larabell (Director of the Na- full-body CAT scanning, was tier science that we continue today, as was pointed out explicitly tional Center for X-Ray Tomog- enormously enthusiastic about in the recent BES review. As a teacher and researcher, Daniel was raphy). The BCSB has five the potential of the new tech- inspirational for his students and colleagues. Along with his ex- beamlines optimized for macro- nique and told the assembled tensive network of friends, I will greatly mourn his passing, while molecular protein crystallography. group, “I love this stuff!” Near- appreciating his extraordinary life.” The NCXT carries out research ing the end of the NCXT tour, Daniel is survived by his wife Berit, two children, Yann, an as- in biological and biomedical im- Mark Le Gros, the Berkeley Lab sistant professor of physics at the University of Illinois, Urbana- aging and cell biology. scientist responsible for the de- Champaign, and Britt Chemla Jones, an art history lecturer in Director Zerhouni's tour of sign and construction of the Houston, Texas. To read the full obituary on the ALS Web site, go the BCSB beamlines included a new microscope, showed Zer- to http://www-als. lbl.gov/als/news/chemla.html. look at Beamline 5.0.3's new 315r houni his latest innovation, an CCD detector and the Berkeley instrument for a technique Gary Krebs, the popular leader of the ALS User Automounter System (developed known as correlated mi- Services Group, passed away suddenly on the by Thomas Earnest and col- croscopy. At the end of his in- evening of May 22, 2007, in the midst of travel to leagues at Berkeley Lab). Adams spection of the NCXT beamline, Long Island for his annual visit to attend the Na- described the upcoming up- Director Zerhouni, with overall tional Synchrotron Light Source (NSLS) user meet- grades to Beamlines 8.2.1 and responsibility for the NIH's $29 ing at Brookhaven National Laboratory. 8.2.2, and Zerhouni responded billion budget, beamed and Since arriving at the ALS in 1993, Gary had ma- enthusiastically about the pros- said, “This was money well jor impacts in several important areas: bringing pects for increased automation spent!” the nascent accelerator survey and alignment system into adult- hood as a functioning, productive tool, leading the first User Serv- ices Group as it evolved to serve an ever-larger user community, and as the ALS representative to the Lab group that has been for- mulating plans for the on-site Berkeley Lab Guest House. For the last two years, he also served as Deputy Scientific Director to the late Neville Smith and then as Deputy Science Advisor to Janos Kirz. “Over the past three years I had the privilege to work closely with Gary, and I learned a lot from him,” said Janos. “He was de- voted to the ALS, and in particular to the users of the ALS. He worked hard to make the Guest House a reality, and his efforts are now bearing fruit. His passing is a great loss to all of us, and to me personally.” In addition to his wife Kathy, he leaves behind one son, Matthew, and in Vancouver, British Columbia, a brother, Dennis, and his parents. To read the full obituary on the ALS Web site, go NIH Director Elias Zerhouni, NCXT Director Carolyn Larabell, and to http://www-als.lbl.gov/als/news/krebs.html. former Berkeley Lab Deputy Director Graham Fleming at the NCXT. 13

PEOPLE AND EVENTS

2008 Beam Instrumentation Workshop

The 13th biennial meeting of the Beam Instrumentation Work- shop (BIW) took place at Lake Tahoe on May 4–8, 2008. It was sponsored by Berkeley Lab's Accelerator and Fusion Research, En- gineering, and ALS divisions. This international conference on beam diagnostics and instrumentation for accelerators is probably the most important gathering in the field of beam instrumentation, together with its European counterpart, the Diagnostics for Parti- cle Accelerators Conference (DIPAC), which alternates with BIW Left to right: Julien Bergoz (Faraday Cup Award sponsor), Suren on alternate years. The conference offers formal presentations, a Arutunian (2008 Faraday Cup Award recipient), and Fernando San- poster session, and informal discussions to promote the exchange nibale (BIW08 chair). of ideas and issues between scientists, engineers, and representa- tives of companies operating in the field. Approximately 120 peo- Coherence 2007 Workshop Draws Record Attendance

Interest in coherent x-ray science is increasing rapidly, both in the areas of diffraction microscopy and x-ray photon correlation spectroscopy. The first workshop devoted to these topics was held in Berkeley in 2001. This was followed by gatherings in Cairns, Australia (2003), and Porquerolles, France (2005). The most recent workshop took place at the Asilomar Conference Center near Monterey on June 25–28, 2007. It was attended by 150 practi- tioners (50 more than anticipated) from all parts of the world. In addition to more than 30 talks, 70 posters were presented, show- casing progress on both the experimental and theoretical fronts. In addition to ongoing work and plans for new beamlines at third-gen- BIW08 conference attendees pose for a group photo outside the eration light sources, new results from FLASH [the x-ray free-elec- Granlibakken Conference Center and Lodge near Lake Tahoe, tron laser (FEL) in Hamburg] and from laboratory-scale x-ray California. lasers were discussed, as well as plans for experiments at x-ray FELs under construction on three continents. The workshop was sponsored by the ALS, the Center for X-Ray ple attended, tutorial sessions served as introduction to relevant Optics, Lawrence Livermore National Laboratory, and the Center topics, and a vendor exhibition allowed participants to get updated for Biophotonics at the University of California, Davis. The poster information on related commercial products. sessions and banquet were further enlivened by refreshments The Faraday Cup Award, which recognizes and encourages in- generously contributed by XRADIA. The program and abstracts novative achievements in the field of particle accelerator beam in- can be found on the conference Web site at http://www- strumentation, was presented during the workshop. The award als.lbl.gov/coherence2007/. consists of a money prize and a certificate, and the BIW program committee is solely responsible for the selection of the recipient. This year's winner is Suren G. Arutunian, of the Yerevan Physics Institute, Yerevan, Armenia, for the development, publication, and successful testing of the diagnostic system, “Vibrating Wire Scanner.” Fernando Sannibale of the ALS Accelerator Physics Group was the BIW08 chair this year, and the local organizing committee was coordinated by Joy Kono of the ALS. Berkeley Lab's contribution included three invited talks, one contributed talk, and two posters. More information on BIW08 and its program (including PDF files of the presentations) can be found at the conference Web site at http://www-als.lbl.gov/biw08/. The proceedings of the conference will be published on the Joint Accelerator Conferences Website (JA- CoW), the free-access database for particle accelerator confer- ences, at http://accelconf.web.cern.ch/AccelConf/. Asilomar Conference Center. 14

PEOPLE AND EVENTS

grams. Freelon accepted the a tradition that Honors and Awards award at Morehouse College on began in 1874, April 5 and gave a talk entitled are chosen by ALS user Franz Himpsel won tures, writing and experimental “Probing High-Temperature Su- their peers for the 2007 Davisson-Germer Prize research in the area of nano- perconductors with Layers and their distin- “for pioneering magnetism, magnetic films, mul- Light.” Freelon attended Prairie guished contri- investigations of tilayers and surfaces of metallic View A&M University and re- butions to sci- the electronic systems, including championing ceived a Ph.D. in physics from the Feinberg ence research, structure of sur- the surface magneto-optic Kerr University of Minnesota in 2001. teaching, tech- faces, interfaces, effect approach.” The award nology, or administration. Ben adsorbates, and was presented at the March Chuck Fadley, long-time ALS was elected “for outstanding nanostructures.” meeting of the American Phys- user, ALS Professor, and a contributions to user facilities, Himpsel Himpsel has ical Society, where Bader gave physicist with Berkeley Lab's especially the Advanced Light been a long- an invited talk in the awards Materials Sciences Division and Source.” Ben and the other new time involved and dedicated session of the Division of Mate- at UC Davis, was presented with fellows were recognized for ALS user. He was part of the rials Physics. Bader is an Ar- an award from their contributions at the Fel- group that argued for the estab- gonne Distinguished Fellow and the Japanese lows Forum on February 16, lishment of the ALS, was currently serves as Chief Scien- Society for the 2008, during the AAAS Annual among the team that built one tist of the new Center for Promotion of Meeting in Boston. of the first two undulator beam- Nanoscale Materials and as As- Science for his lines, and later took part in the sociate Division Director and development of Howard Padmore, ALS Division development of a nano-NEX- group leader in Argonne's Ma- characterization Deputy for Ex- AFS endstation at Beamline terials Science Division. Fadley methods based perimental Sys- 8.0.1. He served on the ALS Sci- on photoelec- tems, has been ence Policy Board and Users' Former ALS postdoc and cur- tron spectroscopy and synchro- elevated to the Executive Committee. Himpsel rent user Byron tron radiation and for his men- rank of fellow is a pioneer in the field of sur- Freelon has been toring of young scientists. Fadley by the Optical face science using synchrotron awarded the received the award while at- Society of Amer- radiation and is also a long-time first Morehouse tending the Sixth International Padmore ica (OSA) Board user of the Synchrotron Radia- Prize by the Na- Symposium on Atomic-Level of Directors at their meeting in tion Center (SRC) in Madison tional Society of Characterization for New Mate- September 2007 in San Jose, Cal- and served as its Scientific Di- Black Physicists rials and Devices in Kanazawa, ifornia. OSA members who rector from 1997 to 2002. Freelon (NSBP), which Japan. He is one of the world's have served with distinction in recognizes grad- foremost practitioners of photo- the advancement of optics are Sam Bader, member and past uates of historically black col- electron spectroscopy. eligible for nomination to the chair of the ALS leges and universities who have rank of fellow. The number of Scientific Advi- shown considerable promise as In 2007, ALS Deputy Division fellows is limited to ten percent sory Commit- physics researchers and teach- Director Ben Feinberg (now re- of the total membership. The tee, received the ers. The prize was awarded for tired) was one of five Berkeley Society recognizes Howard for 2007 David his work in x-ray Raman scat- Lab scientists selected as a fel- his pioneering contributions to Adler Lecture- tering on artificial supercon- low of the American Associa- the application of x-ray optics to ship Award for ducting materials and his strong tion for the Advancement of scientific research using syn- Bader his “spirited lec- support of NSBP student pro- Science (AAAS). AAAS fellows, chrotron radiation. 15

PEOPLE AND EVENTS

ergy's Office of Basic Energy bacterial metalloproteins. She New Faces Sciences (BES) detector and ac- also performed research on en- celerator R&D initiative that is zymes in the sulphur cycle and Peter Denes of Berkeley Lab's generation light source. A pri- slated for FY 2008 and will en- secretion systems of pathogenic Engineering Division has joined mary component of his job will hance Berkeley Lab's ability to bacteria. the ALS as our Deputy for En- be the ALS detector program. do research in this area. In 2003, Sue came to the gineering. “Peter has been a “This program is a virtual um- ALS for a two-year stint as a leader within Engineering and brella that brings together talent Sue Bailey recently joined the beamline scientist in the Berke- in detector development at the from the ALS, Engineering, and ALS as leader of the User Serv- ley Center for Structural Biol- Lab, and we're now looking for- Physics to focus on the detector ices Group, which includes the ogy. This evolved into a posi- ward to his playing a larger role needs of the ALS,” stated Peter. User Services Office, Commu- tion as the BCSB's user support in these efforts for the ALS,” “Detectors can be purchased nications Section, and Experi- manager for the ALS protein said Roger Falcone, ALS Divi- from manufacturers, but the mental Setup Coordination. She crystallography beamlines. Sue sion Director. unique requirements of the ALS brings to her new position over returned to England and to In the Engineering Division, beamlines often require unique 20 years of scientific, software, Daresbury, but was soon lured Denes was responsible for elec- detectors which are not avail- and managerial experience. Sue back to the Bay Area and the tronics, software, and instru- able commercially.” This new also has the perspective of ALS. “I'm pleased and honored mentation engineering and program aims to help users working at two synchrotron fa- to again be part of this world- brings this expertise to his new with existing detectors as well cilities, Daresbury Synchrotron class facility,” she stated. “I have position. Peter's dedicated and as to develop novel detectors Radiation Source in the United an open-door policy, and all on-site presence will provide that will improve ALS science. Kingdom and the ALS. At users are welcome to drop in.” tighter coupling between the As the detector program gets off Daresbury, she was the group Sue's office is in Building 6, Engineering Division and the the ground, Peter also antici- leader and user point of contact Room 2212D, within the User ALS, more integrated manage- pates incorporating a postdoc in the European community for Services Office. You can also ment of engineering resources program where new engineers a protein crystallography com- contact her by email at SBai- within the ALS, and a long- can be mentored and trained. putational project and led her [email protected] or telephone at range focus as the ALS looks to This detector program antici- own research team on struc- 510-486-7727. its future as well as to the next- pates the Department of En- ture-function relationships of

Peter Denes. Sue Bailey. 16

FACILITY Accelerator Availability and Reliability HOURS SCHEDULED AND DELIVERED UPDATES Scheduled Delivered Availability Mean time between hours hours* failures (hours) by David Robin FY05 5600 5344 95.4% 40 The ALS operating schedule of scheduled and delivered user FY06 6201 6045 97.5% 50 is divided into user beam shifts, hours were rather different in accelerator physics/machine those two years. Because of this FY07 4200 3864 92.0% 51 setup shifts, maintenance and anomaly, it is convenient to installation shifts, and vacation look at the availability over the *Does not include unscheduled hours delivered to users. shutdown shifts. In a “typical entire three years. Of the 16,001 year,” there is usually one long scheduled hours, the ALS de- shutdown for major servicing, livered 15,253 hours, which av- large installations, and up- erages to 5083 hours per year, grades. This long shutdown and with a total availability of User Demographics and Publications associated startup usually oc- 95.3% delivered in schedule. curs in the spring and lasts There was a drop in avail- As a national user facility, the ALS is required to report user about six weeks. Also, in a typ- ability in FY07. This was be- demographics and publication information annually to the U.S. ical year the ALS schedules and cause of two cascading effects Department of Energy. Figure 1 shows the growth in particular delivers more than 5000 beam that arose from the injector up- scientific fields and the overall user growth from 1998–2007. The hours to users. Below is a sum- grade. In the fall of 2006, the drop-off in 2007 is attributable to the fact that there were two mary of events during the pre- ALS underwent a major shut- long shutdowns in FY07 as opposed to just one, as in a typical vious three fiscal years and the down to install and commission year. The breakdown of different types of institutions that make availability and reliability of the components necessary for full- up our user base is shown in Figure 2. The growth of the user facility. energy injection. At the end of community over the past 10 years is mirrored by the growth in Availability is one of the the shutdown, there was a ma- beamlines and publications, as shown in Figure 3. As the num- most important performance jor failure in one of the compo- ber of beamlines approaches the capacity of the storage ring, parameters of the facility. Avail- nents (the booster bend power new beamlines will be created by chicaning straight sections ability is defined as the ratio of supply), which resulted in a loss and revamping some of the older bend-magnet beamlines. delivered versus scheduled user of nine user days. The second time, while reliability is defined effect was that this failure re- as the ratio of the number of ac- sulted in longer fill times for tual fills that were completed the remainder of FY07. without interruption versus the Reliability is another impor- number of scheduled fills. tant performance parameter of Maintaining a high availability the facility, which is distinct as the facility becomes more from availability. Reliability is mature and complex (e.g., the defined as the ratio of the num- addition of new insertion de- ber of actual fills that were vices, injector upgrades, feed- completed without interruption back and feed forward) is a versus the number of scheduled challenging task. fills. Providing good availability The number of hours sched- is necessary but not sufficient to uled and delivered is shown in ensure good reliability. For ex- the table. In this review period, ample, a user run with many Figure 1. Bar graph showing growth in areas of science. The there was a deviation from the unscheduled dropouts but fast 2007 numbers reflect the two shutdowns that occurred in typical yearly shutdown pattern recovery times would result in FY07. as described above. In FY06 the good availability but poor relia- ALS ran the entire year without bility. A good measure of relia- a major shutdown, and in FY07 bility is the mean time between the ALS had two long-term failures (MTBF). The MTBF shutdowns—one in the fall of was 40 hours in FY05 and in- 2006 and the other in the spring creased to 50 hours in FY06 and of 2007. Therefore, the number 51 hours in FY07. continued on page 17 17

that is not compatible with ALS which will improve our support FACILITY Construction Projects Update user operations due to vibra- for our users. UPDATES tions. Work on this phase Design work on the 57- should be completed around room Berkeley Lab Guest House The User Support Building plan to break ground during the the end of the calendar year. is substantially complete. Con- project team has been working September 2008 shutdown to The next phase will begin in struction on the site began with to minimize the impacts of the install the foundations, under- spring/summer 2009 and will mass excavation activities to directed funding change for the ground utilities, and major ver- include the remainder of the ready the building pad. Foun- project this fiscal year ($5M in- tical steel columns. The six-week structural steel and exterior dations are currently being in- stead of the planned $17M). We shutdown, beginning on Sep- skins of the building. This stalled. We anticipate construc- are moving forward with a tember 2nd, was scheduled to phase be will completed around tion of the relatively simple phased-construction model and accommodate construction work the end of calendar year 2009. wood-framed structure to be The final project phase will be- completed in June 2009 and the gin in spring/summer 2010 and Guest House to be open for include the entire interior of the guests shortly thereafter. We are User Demographics and Publications continued from page 16 building. Depending on how currently working with the UC early the funding for the 2010 Berkeley Residential and Student ALS User Institutions fiscal year arrives, the project Service Program to finalize an (2158 total users) will be completed in either late agreement to operate the Guest 0% 4% 2010 or early 2011. We are thrilled House. Once this agreement is that we are moving moving for- in place we will be able to de- 11% LBNL ward on this critical facility, termine the final room rates. 32% 4% Other DOE Labs Other US Government 6% University Industry Foreign Labs Foreign Universities Foreign Industry 6% Other 0% 37%

Figure 2. Pie chart showing percentages of different types of user institutions.

Beamlines/Publications 1995–2007* 50 700 User Support Building. 45 600 40 35 500

30 400 25 20 300 Beamlines Publications 15 200 10 100 5 0 0

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Year

Figure 3. Graph of growth in beamlines (pink) and publica- tions (blue). *Note that publications for 2007 were still being collected at the time this section was being written. Berkeley Lab Guest House. 18

described in The 10 Basic Re- FACILITY The ALS Moves Forward: New Initiatives search Needs Workshop Reports. UPDATES The EFRCs will focus on the scientific breakthroughs needed We are in the process of tending from single-investigator for advanced energy technolo- submitting a variety of funding and small-group research (SISGR) gies. Examples of research areas requests to DOE, ranging from to Energy Frontier Research include the direct conversion of a theory program, to detector Centers (EFRCs). Funding for new solar energy to electricity and development, to research on en- awards under these programs chemical fuels, biological feed- ergy problems, to the rebuilding should be available in FY09, stock conversion into portable of Sector 7, and more, all in an- pending appropriations. The re- fuel, and new radiation-tolerant ticipation of new programs that search and instrumentation areas materials. The SISGR grants Congress and the President seem covered include those outlined cover areas such as ultrafast sci- poised to support in the next in the Grand Science Challenges ence, chemical imaging, com- fiscal year. For example, a recent Report of the Basic Energy Sci- plex materials research, and in- DOE call for proposals spans a ences Advisory Committee, and strumentation. wide range of activities, ex- Use-Inspired Discovery Science, as continued on page 19 BES Grand Challenges Report.

Science Roundup continued from page 3 versity, and Lawrence Livermore Toward Curing Autism National Laboratory has used x-ray Araç et al., Neuron 56, 992 (2007) of 102 gold atoms surrounded by Squeezing Iron diffraction at very high pressure http://www-als.lbl.gov/als/science/ 44 molecules of a thiol compound Speziale et al., J. Geophys. Res. to investigate the effects of this sci_archive/165autism.html (para-mercaptobenzoic acid, or p- 112, B10212 (2007) transition on the elastic properties Establishment of neural connec- MBA). The central gold atoms are http://www-als.lbl.gov/als/science/ of magnesiowüstite (Mg1–xFex)O, tions at specialized intercellular grouped in a fivefold symmetric sci_archive/166iron.html the second most abundant min- junctions called synapses is crit- packing arrangement known as a It is now known that the iron pres- eral in the Earth's lower mantle. ical for proper brain function, and Marks decahedron, which is sur- ent in minerals of the lower mantle The new results suggest that the errors in the process are thought rounded by additional layers of gold of the Earth undergoes a pres- effect of the spin-pairing transition continued on page 20 atoms in unanticipated geometries. sure-induced transition with pair- on magnesiowüstite can be large The protective p-MBAs interact ing of the spins of its 3d electrons. enough to require a partial revi- not only with the gold but with A team from the University of sion of the most accepted model of one another, forming a rigid sur- California, Berkeley, Tel Aviv Uni- the lower mantle composition. face layer. This research is a suc- cess on several levels. The group developed a technique that solves

a previously unsolvable nanos- ) 3 5.5 tructure. They delivered a very detailed atomic map of this struc-

ture, which itself reveals an un- kg/m 3 usual discovery: the discrete 5.0 nature of the nanoparticle, which can be explained by the closing of a 58-electron shell. 4.5 (Mg1–xFex)O

Fit to (Mg1–xFex)O spin-unpaired Density (10 Fit to (Mg Fe )O spin-paired Model for the arrangement of the 1–x x β 4.0 neuroligin-1/neurexin-1 complex at the synapse. Neurexins are tethered 020406080 100 120 to the pre-synaptic cell membrane Pressure (GPa) (top) and neuroligins are tethered

Pressure dependence of the density of (Mg1 –1xFex)O (x = 0.17 and 0.2) to the post-synaptic cell membrane shows an anomalous change in slope, modeled as a “mixed-state” region (bottom) by their stalk regions. where iron with spin-paired and spin-unpaired 3d electron configurations Their interaction provides trans- coexist in the structure of magnesiowüstite. synaptic connectivity. 19

MAESTRO NanoARPES New Initiatives continued from page 18

Together with users, the initiate stronger interactions be- MicroARPES ALS is proposing a collabora- tween experimentalists and the- Coherent tion involving the Berkeley oreticians. Imaging campus and Stanford called the Proposals for rebuilding Sec- Theory Institute for Photon Sci- tor 7 of the ALS focus on the Coherent ences (TIPS), which will pro- MAESTRO and COSMIC in- Scattering vide theoretical support to the struments; this remains a pri- COSMIC users of existing and future ority in our strategic plan. The light source facilities in meeting Microscopy and Electronic Struc- the Grand Challenges. One of ture Observatory (MAESTRO) Depiction of the COSMIC and MAESTRO beamlines on the ALS the missions of TIPS will be to continued on page 20 floor at Sector 7.

This required an upgrade of tor. The goal for summer 2008 is Top-Off continued from page 1 parts of the booster synchrotron to slowly increase the peak stored (particularly rf components, power current to 500 mA. This will re- for all sources—insertion de- beam sizes, and smaller vertical supplies, diagnostics and controls) sult in an increase in average vices as well as bend and su- gaps. as well as an upgrade of the some flux and brightness even before perbend magnets. These gains For top-off injection to of the pulsed-injection elements. full top-off operation. result from the doubling of the work, the injector energy had to With the completion of the 2006 Also in 2007 and 2008, a set average current, smaller vertical be increased from 1.5 to 1.9 GeV. shutdown and commissioning of very extensive radiation safety period, the major hardware studies were performed, an im- 600 work for the top-off upgrade portant activity to be completed Δt δt was complete. However, although before top-off operation can be- 400 all the hardware installations gin. Top-off operation requires δi were completed at the end of 2006, that the beamline shutters re- 200 the new power supply for the main open during injection. Current (mA) Current Time-average current increased booster dipole chain failed dur- There has been good progress, by a factor of 2 ing the final testing conducted culminating in an outside peer 0 0 81624 by the vendor. This caused sev- review of the tracking studies, Time (h) eral days’ delay in user startup in demonstrating that injection Sketch of the beam current history during one day before and January 2007 and subsequently with the safety shutters open is after top-off. limited performance. A success- safe, given certain controls in- ful collaborative effort between volving interlock systems and 24.1 the vendor and ALS engineers verification of all necessary during the Thanksgiving shut- apertures. This includes the in- down in November 2007 re- stallation of some new aper- 24 solved the problem. tures. All additional interlock The first beam operation of systems and apertures neces- the booster synchrotron at up to sary to ensure safe operation in 1.9 GeV occurred on December 3, top-off mode will have been in- C] o 23.9 2007. During the following week, stalled by the beginning of 2009. T [ injection rates into the storage The process that leads to regu- ring were improved, and full- latory approval for top-off oper- energy injection became stan- ation was started in late summer 23.8 dard on December 11. Once 2007 and we hope to receive ap- full-energy injection was imple- proval in August 2008. We an- mented, an immediate benefit ticipate beginning initial top-off 23.7 became obvious: transients in operation on most of the beam- 0 5 10 15 20 air and cooling water tempera- lines during some accelerator t [h] tures—previously caused by the physics shifts in fall 2008 and Average air temperature in the ALS accelerator tunnel for a typical change in magnet currents for then begin full top-off operation day with injection at 1.5 GeV (blue) as well as with full energy in- injection—disappeared, resulting for all beamlines during user jection (red), showing the improved thermal stability. in better stability of the accelera- time beginning in early 2009. 20

Science Roundup continued from page 18 New Initiatives continued from page 19 to be associated with autism and tions in the neurexin and neuroligin will address the need for im- the ALS, with an initial empha- other disorders. Researchers from genes are among the multiple ge- provement of spatial and en- sis on the needs of new beam- Stanford University and the Uni- netic causes of autism, under- ergy resolution for photoemis- lines such as MAESTRO and versity of Texas Southwestern standing the molecular mechanism sion. Coherent Scattering and COSMIC. Medical Center have reported high- of these proteins in synapse de- Diffraction Microscopy (COS- It is important to note that resolution, three-dimensional struc- velopment is a first step towards MIC) will provide improved, in- although growth at the ALS and tures of the proteins, called neuro- development of novel therapeutics tense coherent light in the 0.5–3 other national facilities has been ligin-1 and neurexin-1β, that form directed to treat and possibly keV range with full polarization limited under recent federal this connection. Because muta- cure autism. control. budgetary restraints, new op- We also see opportunities portunities for funding continue for advances in how we gener- to arise. We strongly encourage ate and detect photons. We have our users and staff to bring for- submitted two proposals—one ward new ideas to take advan- for advanced accelerator R&D tage of such opportunities. We toward a next-generation light can provide important assis- source and one for advanced x- tance in bringing such proposals ray detector technology. The to funding agencies, foundations, detector proposal is specifically etc. Partnerships among users and For information about using August 2008 tuned to the soft x-ray needs at the ALS can be very persuasive. the ALS, contact: Ernest Orlando Lawrence Berkeley National Laboratory ALS User Services Office University of California Advanced Light Source Berkeley, California, 94720- Lawrence Berkeley National 8235 Laboratory MS 6R2100 This work was supported by Berkeley, CA 94720-8226 the Director, Office of Tel: (510) 495-2001 Science, Office of Basic En- Fax: (510) 486-4773 ergy Sciences, of the U.S. De- Email: [email protected] partment of Energy under Contract No. DE-AC02- MARK YOUR CALENDARS, ALS home page 05CH11231. http://www-als.lbl.gov/ 2009UPDATE YOUR BLACKBERRIES! Editors: Lori Tamura ALS Users’ Meeting Elizabeth Moxon Julie McCullough OCTOBER 15–17, 2009 Arthur Robinson

Design, layout, photography, and additional writing pro- vided by the Creative Services Office and the Communica- tions Department of Berkeley Lab’s Public Affairs Depart- ment.

The editors gratefully ac- knowledge the ALS users and staff for their contributions, advice, and patience.