Science with Neutrons and Muons Research at the Paul Scherrer Institute an Experiment with Muons Is Being Prepared

Total Page:16

File Type:pdf, Size:1020Kb

Science with Neutrons and Muons Research at the Paul Scherrer Institute an Experiment with Muons Is Being Prepared Science with neutrons and muons Research at the Paul Scherrer Institute An experiment with muons is being prepared. Contents 4 Neutrons and muons 18 Discovering materials in 90 seconds 18 Microgels 19 Making smart materials 6 Energy and transport 19 Understanding superconductors 6 Seeing batteries from the inside 20 Engaging with industry 6 Refining motorcycle fuel efficiency 7 Stress-testing turbine blades 20 Universities, industry and PSI 21 Solving industry problems 21 Developing new technologies 8 Earth and environment 21 Spin-off company 8 Cleaning soil with poplar trees 21 A future neutron source for Europe 8 Water in clays 9 Watching plants grow 22 Inside the Swiss Muon Source SμS 10 Food, health and medicine 24 Using neutrons and muons 10 Secret life of bubbles 25 What is a neutron? 10 A recipe for healthy eating 25 What is a muon? 11 Copying nature for medicine 26 Making neutrons and muons 12 Inside the Swiss Spallation 26 Accelerating protons Neutron Source SINQ 26 Making neutrons 26 Making muons 14 Heritage and culture 14 Making a Bronze Age axe 28 We make it work 15 Predicting salt damage to buildings 31 PSI in brief 16 Electronics and technology 1 3 Imprint 16 Spintronics 31 Contacts 16 Measuring grains of magnetism 17 Molecular sandwiches Cover photo Experiments with neutrons and muons allow scientists to measure inside materials and find out where atoms are and what they are doing. 3 Neutrons and muons in 90 seconds The Paul Scherrer Institute PSI, is Neutrons are abundant particles in home to three large research facilities: nature. Along with protons and elec- the Swiss Spallation Neutron Source trons, they make up atoms, the basic SINQ, the Swiss Muon Source SμS, and building blocks of the natural world. the Swiss Light Source SLS. PSI is the Neutrons are tightly bound up with largest natural and engineering protons in the nucleus at the centre of sciences research centre in Switzer- an atom. land. Muons are elementary particles that can be embedded in the gaps between atoms inside a material to sense what Using the large research facilities at is around them. They have an electric PSI, scientists can get an outstanding charge and are heavier than an electron view of the inside world of materials. but lighter than a proton. Their measurements connect the mi- croscopic positions and movement of Over 2500 scientists travel to PSI every atoms with the properties experienced year from Switzerland and around the in the everyday world. world. Among others they use the beams of neutrons and muons to illu- The comforts and convenience of mod- minate their materials and discover ern life rely on many decades of re- their microscopic properties. search and development by scientists and engineers. Through their careful Every day, discoveries from PSI are explorations, the potential uses of nat- being used to advance science and ural and artificial materials can be re- solve problems in industry. alised. You can read more about PSI research Materials are everywhere. Lightweight using neutrons or muons in the follow- bikes and fuel-efficient cars, surgical ing pages. implants, energy efficient homes, car- rying fresh food from supplier to super- market every day, mobile phones for instant connection to family and friends, and much more. http://psi.ch/X135 At PSI, beams of neutrons and muons are used for materials research. The beams are made by firing protons from a particle accelerator into targets made of lead or carbon. A fantastic piece of Swiss engineering, the accelerator http://psi.ch/HkxX makes the most powerful beam of pro- tons in the world. 4 The comforts and convenience of modern life would be impossible without many decades of research into new materials. 5 Energy and transport As demand for energy continues to Using neutron beams, it is possible to in volume would make it very difficult increase, ways to reduce fuel consump- see inside a battery and follow what is to guarantee the battery would work tion and improve energy efficiency are happening in real time to the battery after it had been charged many times. a growing concern. Neutron and muon parts as it is charged and discharged. beams at PSI are increasingly being This gives unique insight into the real used for energy related research. operating performance of the battery. Refining motorcycle fuel With muon beams, the movement of efficiency chemicals around the battery can be followed. Neutron beams can shine right through Seeing batteries from the For instance, the microscopic changes metals. This property has been put to inside to the volume of a metal hydride can good use by engineers designing a be watched as hydrogen is absorbed clutch lubricated with oil. To their sur- Rechargable batteries are used every- during charging. Good commercial ma- prise, many discs were found to be where in toys, electronics and electric terials have a smooth and reversible running dry. Time to go back to the vehicles. Common nickel-metal hy- change in volume. But if a possible new drawing board. dride batteries were once just labora- battery material makes a sudden jump tory curiosities. Now, materials devel- in volume rather than a smooth change, Motorcycle engineers are under con- oped in the last 20 years allow them it is not suitable. Such sudden changes stant pressure to reduce fuel consump- to be recharged many times. Battery development is a continuous process and neutron and muon beams at PSI are regularly used by manufacturers. A typical AA-type nickel-metal hydride battery (NiMH) is a compact wonder of science you can carry around in your pocket. Inside the battery, two metal strips sep- arated by an insulating foil are rolled up and placed into the metal can. The can is filled with an electrically conduct- ing liquid and sealed with a cap. The positive terminal is made from a nickel compound and the negative ter- minal is made from a substance known as a metal hydride. As the battery is charged, chemical reactions cause hydrogen to be re- leased from the nickel compound and be soaked up into the metal hydride. Scientists preparing a neutron When the battery is used, the chemical scattering experiment for research reactions reverse and an electrical cur- on new materials for batteries. rent flows out. 6 tion to meet efficiency and emissions made the surprising discovery that only gruelling conditions is crucial for im- targets and increase the driving range the first three out of eight discs were proving energy efficiency and guaran- of their machines. The oil pump is one being coated with oil. This did not teeing long-term reliability. of the biggest consumers of power from change with engine running speed or the engine. One of its main tasks is to how fast oil was pumped in. Conditions inside gas turbines are ex- lubricate and cool the bike’s clutch. Equipped with such precise informa- treme. Turbine blades can be rotating at The clutch transfers power and motion tion, the internal design of oil flow 3600 revolutions per minute, with hot from the engine to the wheels. The channels in the clutch can be adapted gases at 1400°C flowing through and most common design uses a row of to achieve good lubrication and cooling raising blade temperatures to 1000°C. plates and friction discs that are nor- using reduced oil flows. Engineers must have confidence that mally clamped together, but can be the blades can withstand the extreme pulled apart to change gear. http://psi.ch/zMpn conditions found inside the turbines. Neutron imaging can be used to see Blade materials are only chosen after right through the metal casing and map comprehensive testing of their behav- out where oil is flowing inside the iour to determine how they will per- clutch while it is running at speeds up form. Ongoing improvements to turbine to 8000 revolutions per minute. Stress-testing turbine blades blade materials and design continue In one new clutch design, the aim was to push up efficiency in fuel use and to reduce oil flow through the clutch to Turbines in power stations around the energy conversion. reduce the power consumed by the oil world convert the energy of fast-flow- By placing turbine blades and other pump. Oil is supplied through a hole in ing hot gases into mechanical motion parts in a beam of neutrons, engineers the drive shaft that then runs through to generate electricity. With tempera- can perform in-situ measurements con- the clutch and spreads out onto the tures reaching up to 90% of the melt- necting material behaviour under ap- eight spinning discs of the clutch. ing point of the turbine blades, ongo- plied loads to the microscopic fine Taking neutron snapshots lasting just ing research and development into the structure of the component. In-built 50 millionths of a second, engineers performance of materials under such residual stresses coming from the man- ufacturing process can also be meas- ured. Residual stresses are a significant problem in a component since they can lead to cracks and unpredictable changes in material properties. PSI is a world leader in in-situ engineer- ing stress measurements using neutron beams, attracting visitors from interna- tional engineering companies on a regular basis. In one recent project studying turbine blades, changes in the microstructure of a new design of turbine blade were traced to the casting process used to make the blade. Information from the experiments can be used to optimise the manufacturing procedure and mod- ify the aerofoil design to deliver the best performance and longest operat- ing lifetime. http://psi.ch/H11N 7 Earth and environment Many lessons can be learnt from plants surprisingly, boron can still be ab- and animals on how to solve common sorbed by the leaf into the dead problems and gain a deeper under- patches.
Recommended publications
  • Neutron Stars
    Chandra X-Ray Observatory X-Ray Astronomy Field Guide Neutron Stars Ordinary matter, or the stuff we and everything around us is made of, consists largely of empty space. Even a rock is mostly empty space. This is because matter is made of atoms. An atom is a cloud of electrons orbiting around a nucleus composed of protons and neutrons. The nucleus contains more than 99.9 percent of the mass of an atom, yet it has a diameter of only 1/100,000 that of the electron cloud. The electrons themselves take up little space, but the pattern of their orbit defines the size of the atom, which is therefore 99.9999999999999% Chandra Image of Vela Pulsar open space! (NASA/PSU/G.Pavlov et al. What we perceive as painfully solid when we bump against a rock is really a hurly-burly of electrons moving through empty space so fast that we can't see—or feel—the emptiness. What would matter look like if it weren't empty, if we could crush the electron cloud down to the size of the nucleus? Suppose we could generate a force strong enough to crush all the emptiness out of a rock roughly the size of a football stadium. The rock would be squeezed down to the size of a grain of sand and would still weigh 4 million tons! Such extreme forces occur in nature when the central part of a massive star collapses to form a neutron star. The atoms are crushed completely, and the electrons are jammed inside the protons to form a star composed almost entirely of neutrons.
    [Show full text]
  • The Five Common Particles
    The Five Common Particles The world around you consists of only three particles: protons, neutrons, and electrons. Protons and neutrons form the nuclei of atoms, and electrons glue everything together and create chemicals and materials. Along with the photon and the neutrino, these particles are essentially the only ones that exist in our solar system, because all the other subatomic particles have half-lives of typically 10-9 second or less, and vanish almost the instant they are created by nuclear reactions in the Sun, etc. Particles interact via the four fundamental forces of nature. Some basic properties of these forces are summarized below. (Other aspects of the fundamental forces are also discussed in the Summary of Particle Physics document on this web site.) Force Range Common Particles It Affects Conserved Quantity gravity infinite neutron, proton, electron, neutrino, photon mass-energy electromagnetic infinite proton, electron, photon charge -14 strong nuclear force ≈ 10 m neutron, proton baryon number -15 weak nuclear force ≈ 10 m neutron, proton, electron, neutrino lepton number Every particle in nature has specific values of all four of the conserved quantities associated with each force. The values for the five common particles are: Particle Rest Mass1 Charge2 Baryon # Lepton # proton 938.3 MeV/c2 +1 e +1 0 neutron 939.6 MeV/c2 0 +1 0 electron 0.511 MeV/c2 -1 e 0 +1 neutrino ≈ 1 eV/c2 0 0 +1 photon 0 eV/c2 0 0 0 1) MeV = mega-electron-volt = 106 eV. It is customary in particle physics to measure the mass of a particle in terms of how much energy it would represent if it were converted via E = mc2.
    [Show full text]
  • The Consortium of Swiss Academic Libraries the Consortium of Swiss Academic Libraries
    Research Collection Other Conference Item Times change and we change with them: the Consortium of Swiss Academic Libraries the Consortium of Swiss Academic Libraries Author(s): Boutsiouci, Pascalia Publication Date: 2015 Permanent Link: https://doi.org/10.3929/ethz-a-010439524 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library TIMES CHANGE AND WE CHANGE WITH THEM The Consortium of Swiss Academic Libraries ICoASL – 4th International Conference of Asian Special Libraries 2015 Pascalia Boutsiouci, Seoul, April 23 of 2015 AGENDA 1 Overview Switzerland and Higher Education 2 Overview Consortium of Swiss Academic Libraries 3 Our business – range of activity 4 Cooperation with our partner libraries 5 projects © Consortium of Swiss Academic Libraries | 2015 2 Overview Switzerland 1 and Higher Education © Consortium of Swiss Academic Libraries | 2015 3 THE LANDSCAPE Switzerland lies in the heart of Europe 8.2 million people 26 cantons Four official languages Matterhorn, Zermatt (4,478 m/14,692 ft) / Image source: http://www.zermatt.ch/Media/Pressecorner/Fotodatenbank/Matterhorn/Sicht-aufs- . German (66%) Matterhorn-vom-Gornergrat . French (23%) . Italian (9%) . Rheto- Romanic (1%) Image source: http://en.wikipedia.org/wiki/Switzerland#/media/File:Europe-Switzerland.svg © Consortium of Swiss Academic Libraries | 2015 4 SWITZERLAND = CONFOEDERATIO HELVETICA = CH Federal parliamentary republic consisting of 26 cantons wth Bern as the seat of the federal authorities Germany France Liechtenstein Austria Italy Image source:http://de.wikipedia.org/wiki/Datei:Switzerland,_administrative_divisions_-_de_-_colored.svg © Consortium of Swiss Academic Libraries | 2015 5 HIGHER EDUCATION IN SWITZERLAND Official Higher Education Institutions 10 Cantonal Universities .
    [Show full text]
  • Photons from 252Cf and 241Am-Be Neutron Sources H
    Neutronenbestrahlungsraum Calibration Laboratory LB6411 Am-Be Quelle [email protected] Photons from 252Cf and 241Am-Be neutron sources H. Hoedlmoser, M. Boschung, K. Meier and S. Mayer Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland At the accredited PSI calibration laboratory neutron reference fields traceable to the standards of the Physikalisch-Technische Bundesanstalt (PTB) in Germany are available for the calibration of ambient and personal dose equivalent (rate) meters and passive dosimeters. The photon contribution to H*(10) in the neutron fields of the 252Cf and 241Am-Be sources was measured using various photon dose rate meters and active and passive dosimeters. Measuring photons from a neutron source involves considerable uncertainties due to the presence of neutrons, due to a non-zero neutron sensitivity of the photon detector and due to the energy response of the photon detectors. Therefore eight independent detectors and methods were used to obtain a reliable estimate for the photon contribution as an average of the individual methods. For the 241Am-Be source a photon contribution of approximately 4.9% was determined and for the 252Cf source a contribution of 3.6%. 1) Photon detectors 2) Photons from 252Cf and 241Am-Be neutron sources Figure 1 252Cf decays through -emission (~97%) and through spontaneous fission (~3%) with a half-life of 2.65 y. Both processes are accompanied by photon radiation. Furthermore the spectrum of fission products contains radioactive elements that produce additional gamma photons. In the 241Am-Be source 241Am decays through -emission and various low energy emissions: 241Am237Np + + with a half life of 432.6 y.
    [Show full text]
  • Treating Cancer with Proton Therapy Information for Patients and Family Members Professor Dr
    Treating Cancer with Proton Therapy Information for patients and family members Professor Dr. med. Damien Charles Weber, Dear readers Head and Chairman, Proton therapy is a special kind of radiation therapy. For many years now, patients Centre for Proton Therapy suffering from certain tumour diseases have successfully undergone proton radi- ation therapy at the Paul Scherrer Institute’s Centre for Proton Therapy. This brochure is intended to give a more detailed explanation of how proton ther- apy works and provide practical information on the treatment we offer at our facil- ity. We will include a step-by-step description of the way in which we treat deep- seated tumours. We will not deal with the treatment of eye tumours in this brochure. If you have further questions on the proton therapy carried out at the Paul Scherrer Institute, please do not hesitate to address these by getting in touch with our secretaries. Contact details are provided at the end of the brochure. 2 Contents 4 Radiation against cancer 10 Physics in the service of medicine 14 Four questions for Professor Dr. Tony Lomax, Chief Medical Physicist 16 Practical information on treatment at PSI 20 Four questions for Dr. Marc Walser, Senior Radiation Oncologist 22 In good hands during treatment 28 Four questions for Lydia Lederer, Chief Radiation Therapist 30 Treating infants and children 36 Children ask a specialist about radiation 38 PSI in brief Radiation against cancer 4 Because it can be used with great ac- The most important cancer therapies curacy, proton therapy is a particularly are: sparing form of radiation treatment • surgery (operation), with lower side effects.
    [Show full text]
  • Annual Report 2018 Swiss Nanoscience Institute University of Basel
    EINE INITIATIVE DER UNIVERSITÄT BASEL UND DES KANTONS AARGAU Annual Report 2018 Swiss Nanoscience Institute University of Basel Swiss Nanoscience Institute University of Basel Klingelbergstrasse 82 4056 Basel Switzerland www.nanoscience.ch The Swiss Nanoscience Institute (SNI) is a research initiative of the Canton of Aargau and the University of Basel. Swiss Nanoscience Institute Klingelbergstrasse 82 4056 Basel Switzerland www.nanoscience.ch Cover: Atomic force microscopic image of “nano-bone” molecules on a gold surface. The molecule is a buil- ding block for the formation of two-dimensional organic topological insulators (Rémy Pawlak, Department of Physics, University of Basel). © Swiss Nanoscience Institute, March 2019 Content 3 Foreword 4 Swiss Nanoscience Institute — The interdisciplinary center of excellence for nanosciences in Northwestern Switzerland 6 Network 8 News from the network 14 The Paul Scherrer Institute – 30 years old and a key partner on the SNI network 16 Nano Study Program 18 Glued wounds heal better – Tino Matter wins the prize for the best master’s thesis 20 Discussing science at SmallTalk – Students organize their own symposium about the block courses 22 PhD School 24 SNI PhD School – An excellent start of a scientific career 29 Multiple awards – Daniel Riedel wins several prizes 30 SNI Professors 32 Martino Poggio studies nanowires – These tiny wires with special properties have a variety of potential applications 34 Roderick Lim researches the transport processes and mechanical properties of cells – Promising
    [Show full text]
  • Muon Decay 1
    Muon Decay 1 LIFETIME OF THE MUON Introduction Muons are unstable particles; otherwise, they are rather like electrons but with much higher masses, approximately 105 MeV. Radioactive nuclear decays do not release enough energy to produce them; however, they are readily available in the laboratory as the dominant component of the cosmic ray flux at the earth’s surface. There are two types of muons, with opposite charge, and they decay into electrons or positrons and two neutrinos according to the rules + + µ → e νe ν¯µ − − µ → e ν¯e νµ . The muon decay is a radioactiveprocess which follows the usual exponential law for the probability of survival for a given time t. Be sure that you understand the basis for this law. The goal of the experiment is to measure the muon lifetime which is roughly 2 µs. With care you can make the measurement with an accuracy of a few percent or better. In order to achieve this goal in a conceptually simple way, we look only at those muons that happen to come to rest inside our detector. That is, we first capture a muon and then measure the elapsed time until it decays. Muons are rather penetrating particles, they can easily go through meters of concrete. Nevertheless, a small fraction of the muons will be slowed down and stopped in the detector. As shown in Figure 1, the apparatus consists of two types of detectors. There is a tank filled with liquid scintillator (a big metal box) viewed by two photomultiplier tubes (Left and Right) and two plastic scintillation counters (flat panels wrapped in black tape), each viewed by a photomul- tiplier tube (Top and Bottom).
    [Show full text]
  • Particle Accelerator Activities at the Paul Scherrer Institut
    PSI Bericht Nr. 17-07 December 2017 Particle Accelerator Activities at the Paul Scherrer Institut Terence GARVEY Paul Scherrer Institut, Villigen, Switzerland 5232 Division of Large Research Infrastructures Invited paper presented at Les Journées Accélérateurs de la Société Française de Physique, Roscoff, 3rd – 6th October, 2017. Resumé Les Activités Accélérateur à l’Institut Paul Scherrer. L'Institut Paul Scherrer exploite deux complexes d'accélérateurs en tant que ‘centre- serveurs’ pour une grande communauté de chercheurs. Il s'agit de l'Accélérateur de Protons à Haute Intensité (HIPA) et de la Source de Lumière Suisse (SLS). HIPA est un cyclotron à protons de 590 MeV. Il sert à produire des neutrons par spallation pour la recherche en physique de la matière condensée et à produire des muons et d'autres particules secondaires pour la recherche en magnétisme et en physique des particules. Le SLS est un anneau de stockage d’électrons de 2,4 GeV utilisé comme source de rayonnement synchrotron de 3ème génération fournissant des photons pour une large gamme de disciplines scientifiques. En plus de ces deux installations, l'Institut met progressivement en service un laser à électrons libres en rayons X (SwissFEL) qui fournira aux chercheurs des impulsions femto-seconde intenses à partir d’une ligne de rayons X ‘dur’ (ARAMIS) et de rayons X ‘mou’ (ATHOS). L'Institut exploite également un cyclotron supraconductrice à 250 MeV (COMET) aux fins de la thérapie par proton. Le centre de thérapie a récemment été équipé d'un troisième « gantry » rotatif qui est en cours de mise en service. Un « upgrade » du système de radiofréquence de HIPA et des projets pour "SLS-2" seront présentés.
    [Show full text]
  • Opportunities for Neutrino Physics at the Spallation Neutron Source (SNS)
    Opportunities for Neutrino Physics at the Spallation Neutron Source (SNS) Paper submitted for the 2008 Carolina International Symposium on Neutrino Physics Yu Efremenko1,2 and W R Hix2,1 1University of Tennessee, Knoxville TN 37919, USA 2Oak Ridge National Laboratory, Oak Ridge TN 37981, USA E-mail: [email protected] Abstract. In this paper we discuss opportunities for a neutrino program at the Spallation Neutrons Source (SNS) being commissioning at ORNL. Possible investigations can include study of neutrino-nuclear cross sections in the energy rage important for supernova dynamics and neutrino nucleosynthesis, search for neutrino-nucleus coherent scattering, and various tests of the standard model of electro-weak interactions. 1. Introduction It seems that only yesterday we gathered together here at Columbia for the first Carolina Neutrino Symposium on Neutrino Physics. To my great astonishment I realized it was already eight years ago. However by looking back we can see that enormous progress has been achieved in the field of neutrino science since that first meeting. Eight years ago we did not know which region of mixing parameters (SMA. LMA, LOW, Vac) [1] would explain the solar neutrino deficit. We did not know whether this deficit is due to neutrino oscillations or some other even more exotic phenomena, like neutrinos decay [2], or due to the some other effects [3]. Hints of neutrino oscillation of atmospheric neutrinos had not been confirmed in accelerator experiments. Double beta decay collaborations were just starting to think about experiments with sensitive masses of hundreds of kilograms. Eight years ago, very few considered that neutrinos can be used as a tool to study the Earth interior [4] or for non- proliferation [5].
    [Show full text]
  • 2018 Research Slam
    University of St.Gallen (HSG) Centro Latinoamericano-Suizo (CLS-HSG) Leading House for the Latin American Region Müller-Friedberg-Strasse 8 CH-9000 St.Gallen 2018 Research Slam Wednesday, December 19, 2018 / 10:30 to 17:10 hrs Tellstrasse 2, St.Gallen / Room 58-515 Seed Money Grants 2017 Research Merger 2018 Seed Money Grants 2018 Presentation Material of the Winning Projects The Funding Instruments SMG – Seed Money Grants 2017 + 2018 duration: 10 – 12 months grants: CHF 10’000 – CHF 25’000 applications received: 87 / projects awarded: 30 RM – Research Merger 2017 duration: 10 – 12 months grants: CHF 30’000 – CHF 50’000 applications received: 29 / projects awarded: 4 MOB – Mobility Grants 2018 duration: up to 3 months grants: up to CHF 8’000 applications received: 9 / projects awarded: 7 2018 Research Slam 2 / 22 Index Towards the detection of Earth analogues (TDEA). – SMG2017 Damien Ségransan, University of Geneva.............................................................................................................................. 5 Structural colours in natural and artificial multilayers. – SMG2017 Ullrich Steiner, University of Fribourg, Adolphe Merkle Institute .................................................................................. 5 In-operando control of nanoscale decoration of graphene and reduced graphene oxide by novel mini-reactors. – SMG2017 Ivo Utke, Empa, Eidgenössische Materialprüfungs- und Forschungsanstalt (EMPA) ................................................... 6 A dendrogeomorphic reconstruction of
    [Show full text]
  • 03 (15. Februar 2017)
    2017/03 ISSN 1661-8211 | 117. Jahrgang | 15. Februar 2017 Redaktion und Herausgeberin: Schweizerische Nationalbibliothek NB, Hallwylstrasse 15, CH-3003 Bern Erscheinungsweise: halbmonatlich, am 15. und 30. jeden Monats Hinweise unter: http://ead.nb.admin.ch/web/sb-pdf/ ISSN 1661-8211 © Schweizerische Nationalbibliothek NB, CH-3003 Bern. Alle Rechte vorbehalten Inhaltsverzeichnis - Table des matières - Sommario - Cuntegn - Table of contents Inhaltsverzeichnis - Table des matières - 220 Bibel / Bible / Bibbia / Bibla / Bible....................................... 6 Sommario - Cuntegn - Table of contents 230 Christentum, christliche Theologie / Christianisme, théologie chrétienne / Cristianesimo, teologia cristiana / Cristianissem, teologia cristiana / Christianity and Christian theology..................6 000 Allgemeine Werke, Informatik, Informationswissenschaft / Informatique, information, 290 Andere Religionen / Autres religions / Altre religioni / Autras ouvrages de référence / Informatica, scienza religiuns / Other religions............................................................... 9 dell'informazione, generalità / Informatica, infurmaziun e referenzas generalas / Computers, information and general reference........................................................................................ 1 300 Sozialwissenschaften / Sciences sociales / Scienze sociali / Scienzas socialas / Social sciences.......................... 10 000 Allgemeine Werke, Wissen, Systeme / Généralités, savoir, systèmes / Generalità, sapere, sistemi / Generalitads,
    [Show full text]
  • Muon Neutrino Mass Without Oscillations
    The Distant Possibility of Using a High-Luminosity Muon Source to Measure the Mass of the Neutrino Independent of Flavor Oscillations By John Michael Williams [email protected] Markanix Co. P. O. Box 2697 Redwood City, CA 94064 2001 February 19 (v. 1.02) Abstract: Short-baseline calculations reveal that if the neutrino were massive, it would show a beautifully structured spectrum in the energy difference between storage ring and detector; however, this spectrum seems beyond current experimental reach. An interval-timing paradigm would not seem feasible in a short-baseline experiment; however, interval timing on an Earth-Moon long baseline experiment might be able to improve current upper limits on the neutrino mass. Introduction After the Kamiokande and IMB proton-decay detectors unexpectedly recorded neutrinos (probably electron antineutrinos) arriving from the 1987A supernova, a plethora of papers issued on how to use this happy event to estimate the mass of the neutrino. Many of the estimates based on these data put an upper limit on the mass of the electron neutrino of perhaps 10 eV c2 [1]. When Super-Kamiokande and other instruments confirmed the apparent deficit in electron neutrinos from the Sun, and when a deficit in atmospheric muon- neutrinos likewise was observed, this prompted the extension of the kaon-oscillation theory to neutrinos, culminating in a flavor-oscillation theory based by analogy on the CKM quark mixing matrix. The oscillation theory was sensitive enough to provide evidence of a neutrino mass, even given the low statistics available at the largest instruments. J. M. Williams Neutrino Mass Without Oscillations (2001-02-19) 2 However, there is reason to doubt that the CKM analysis validly can be applied physically over the long, nonvirtual propagation distances of neutrinos [2].
    [Show full text]