CODATA Recommended Values of the Fundamental Physical Constants: 2010
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A Doubly-Magic Storage Ring EDM Measurement Method
A doubly-magic storage ring EDM measurement method Richard Talman Cornell University, Ithaca, U.S.A. 10 December, 2018 arXiv:1812.05949v1 [physics.acc-ph] 14 Dec 2018 1 Abstract This paper discusses \doubly-magic trap" operation of storage rings with su- perimposed electric and magnetic bending, allowing spins in two beams to be frozen (at the same time, if necessary), and their application to electric dipole moment (EDM) measurement. Especially novel is the possibility of simultaneous storage in the same ring of frozen spin beams of two different particle types. A few doubly-magic cases have been found: One has an 86.62990502 MeV frozen spin proton beam and a 30.09255159 MeV frozen spin positron beam (with accu- racies matching their known magnetic moments) counter-circulating in the same storage ring. (Assuming the positron EDM to be negligibly small) the positron beam can be used to null the worst source of systematic EDM error|namely, the existence of unintentional and unknown average radial magnetic field < Br > which, acting on the MDM, causes spurious background spin precession indis- tinguishable from foreground EDM-induced precession. The resulting measured proton minus positron EDM difference is then independent of < Br >. This amounts to being a measurement of the proton EDM. Most doubly-magic features can be tested in one or more \small" EDM proto- type rings. One promising example is a doubly-magic proton-helion combination, which would measure the difference between helion (i.e. helium-3) and proton EDM's. This combination can be used in the near future for EDM measurement, for example in a 10 m bending radius ring, using only already well-understood and proven technology. -
Potentialities of a Low-Energy Detector Based on $^ 4$ He Evaporation to Observe Atomic Effects in Coherent Neutrino Scattering and Physics Perspectives
Potentialities of a low-energy detector based on 4He evaporation to observe atomic effects in coherent neutrino scattering and physics perspectives M. Cadeddu,1, ∗ F. Dordei,2, y C. Giunti,3, z K. A. Kouzakov,4, x E. Picciau,1, { and A. I. Studenikin5, 6, ∗∗ 1Universit`adegli studi di Cagliari and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Cagliari, Complesso Universitario di Monserrato - S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari), Italy 2Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Cagliari, Complesso Universitario di Monserrato - S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari), Italy 3Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via P. Giuria 1, I{10125 Torino, Italy 4Department of Nuclear Physics and Quantum Theory of Collisions, Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia 5Department of Theoretical Physics, Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia 6Joint Institute for Nuclear Research, Dubna 141980, Moscow Region, Russia We propose an experimental setup to observe coherent elastic neutrino-atom scattering (CEνAS) using electron antineutrinos from tritium decay and a liquid helium target. In this scattering process with the whole atom, that has not beeen observed so far, the electrons tend to screen the weak charge of the nucleus as seen by the electron antineutrino probe. The interference between the nucleus and the electron cloud produces a sharp dip in the recoil spectrum at atomic recoil energies of about 9 meV, reducing sizeably the number of expected events with respect to the coherent elastic neutrino-nucleus scattering case. We estimate that with a 60 g tritium source surrounded by 500 kg of liquid helium in a cylindrical tank, one could observe the existence of CEνAS processes at 3σ in 5 years of data taking. -
Forward Helion Scattering and Neutron Polarization N
Forward Helion Scattering and Neutron Polarization N. H. Buttimore Trinity College Dublin, Ireland Abstract. The elastic scattering of spin half helium-3 nuclei at small angles can show a sufficiently large analyzing power to enable the level of helion polarization to be evaluated. As the helion to a large extent inherits the polarization of its unpaired neutron the asymmetry observed in helion collisions can be transformed into a measurement of the polarization of its constituent neutron. Neutron polarimetry therefore relies upon understanding the spin dependence of the electromagnetic and hadronic interactions in the region of interference where there is an optimal analyzing power. Keywords: Neutron, spin polarization, helion, elastic scattering, asymmetry PACS: 11.80.Cr, 12.20.Ds, 13.40.Ks, 25.55.Ci, 13.85.Dz, 13.88.+e INTRODUCTION The spin polarized neutrons available from a polarized helium-3 beam would be very suitable for the study of polarized down quarks in various QCD processes particularly relating to transversity [1], nucleon spin structure [2], multi Pomeron exchange [3], gluon distributions [4], and additional dimensions [5]. Measuring the analyzing power in small angle elastic scattering of hadrons with spin provides an opportunity for evaluating the level of polarisation of incident helium-3 nuclei (helions) [6] thereby providing an effective neutron polarimeter [7]. Such a method relies upon an understanding of high energy spin dependence in diffractive processes [8]. Here, the interference of elastic hadronic and electromagnetic interactions in a suitable peripheral region enhances the size of the transverse spin asym- metry sufficiently to offer a tangible polarimeter for high energy helions. -
Metallurgy Materials Programs
WASH-1181-72 METALLURGY and MATERIALS PROGRAMS UNITED STATES ATOMIC ENERGY COMMISSION DIVISION of PHYSICAL RESEARCH LEGAL NOTICE This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor tlhe United States Atomic Energy Commission, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty. express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. WASH-1181-72 METALLURGY AND MATERIALS PROGRAMS Fiscal Year 1972 July 1972 U. S. Atomic Energy Commission Division of Physical Research FOREWORD The Metallurgy and Materials Program constitutes one portion of a wide range of research supported by the AEC Division of Physical Research. Other programs are administered by the Division's Chemistry, High Energy Physics, and Physics and Mathematics Offices. Metallurgy and Materials research is supported primarily at AEC National Laboratories and Univer- sities. The research covers a wide spectrum of scientific and engineering areas of interest to the Atomic Energy Commission and is conducted generally by personnel trained in the disciplines of Solid State Physics, Metallurgy, Ceramics, and Physical Chemistry. This report contains a listing of all research underway in FY 1972 together with a convenient index to the program. Donald K. Stevens Assistant Director (for Metallurgy and Materials Programs) Division of Physical Research i INTRODUCTION The purpose of this report is to provide a convenient compilation and index of the AEC's Metallurgy and Materials Programs. -
Potentialities of a Low-Energy Detector Based on He4 Evaporation to Observe Atomic Effects in Coherent Neutrino Scattering and P
PHYSICAL REVIEW D 100, 073014 (2019) Potentialities of a low-energy detector based on 4He evaporation to observe atomic effects in coherent neutrino scattering and physics perspectives † ‡ ∥ M. Cadeddu,1,* F. Dordei,2, C. Giunti ,3, K. A. Kouzakov ,4,§ E. Picciau ,1, and A. I. Studenikin5,6,¶ 1Universit`a degli studi di Cagliari and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Cagliari, Complesso Universitario di Monserrato—S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari), Italy 2Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Cagliari, Complesso Universitario di Monserrato—S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari), Italy 3Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via P. Giuria 1, I-10125 Torino, Italy 4Department of Nuclear Physics and Quantum Theory of Collisions, Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia 5Department of Theoretical Physics, Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia 6Joint Institute for Nuclear Research, Dubna 141980, Moscow Region, Russia (Received 14 July 2019; published 29 October 2019) We propose an experimental setup to observe coherent elastic neutrino-atom scattering (CEνAS) using electron antineutrinos from tritium decay and a liquid helium target. In this scattering process with the whole atom, that has not been observed so far, the electrons tend to screen the weak charge of the nucleus as seen by the electron antineutrino probe. The interference between the nucleus and the electron cloud produces a sharp dip in the recoil spectrum at atomic recoil energies of about 9 meV, reducing sizably the number of expected events with respect to the coherent elastic neutrino-nucleus scattering case. -
The Treatment of Electronic Excitations in Atomistic Models of Radiation Damage in Metals
REVIEW ARTICLE The treatment of electronic excitations in atomistic models of radiation damage in metals C P Race1, D R Mason1, M W Finnis1 2, W M C Foulkes1, A P Horsfield2 and A P Sutton1 1 Department of Physics, Imperial College, London SW7 2AZ, UK 2 Department of Materials, Imperial College, London SW7 2AZ, UK Abstract. Atomistic simulations are a primary means of understanding the damage done to metallic materials by high energy particulate radiation. In many situations the electrons in a target material are known to exert a strong influence on the rate and type of damage. The dynamic exchange of energy between electrons and ions can act to damp the ionic motion, to inhibit the production of defects or to quench in damage, depending on the situation. Finding ways to incorporate these electronic effects into atomistic simulations of radiation damage is a topic of current major interest, driven by materials science challenges in diverse areas such as energy production and device manufacture. In this review, we discuss the range of approaches that have been used to tackle these challenges. We compare augmented classical models of various kinds and consider recent work applying semi-classical techniques to allow the explicit incorporation of quantum mechanical electrons within atomistic simulations of radiation damage. We also outline the body of theoretical work on stopping power and electron-phonon coupling used to inform efforts to incorporate electronic effects in atomistic simulations and to evaluate their performance. Contents 1 Introduction 3 1.1 The radiation damage cascade . .4 1.2 Transfer of energy between ions and electrons in radiation damage . -
Small-Scale Fusion Tackles Energy, Space Applications
NEWS FEATURE NEWS FEATURE Small-scalefusiontacklesenergy,spaceapplications Efforts are underway to exploit a strategy that could generate fusion with relative ease. M. Mitchell Waldrop, Science Writer On July 14, 2015, nine years and five billion kilometers Cohen explains, referring to the ionized plasma inside after liftoff, NASA’s New Horizons spacecraft passed the tube that’s emitting the flashes. So there are no the dwarf planet Pluto and its outsized moon Charon actual fusion reactions taking place; that’s not in his at almost 14 kilometers per second—roughly 20 times research plan until the mid-2020s, when he hopes to faster than a rifle bullet. be working with a more advanced prototype at least The images and data that New Horizons pains- three times larger than this one. takingly radioed back to Earth in the weeks that If that hope pans out and his future machine does followed revealed a pair of worlds that were far more indeed produce more greenhouse gas–free fusion en- varied and geologically active than anyone had ergy than it consumes, Cohen and his team will have thought possible. The revelations were breathtak- beaten the standard timetable for fusion by about a ing—and yet tinged with melancholy, because New decade—using a reactor that’s just a tiny fraction of Horizons was almost certain to be both the first and the size and cost of the huge, donut-shaped “tokamak” the last spacecraft to visit this fascinating world in devices that have long devoured most of the research our lifetimes. funding in this field. -
Earth-Bound Millicharge Relics
PHYSICAL REVIEW D 103, 115031 (2021) Earth-bound millicharge relics Maxim Pospelov1,2 and Harikrishnan Ramani 3,* 1School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA 2William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA 3Stanford Institute for Theoretical Physics, Stanford University, Stanford, California 94305, USA (Received 29 March 2021; accepted 31 May 2021; published 25 June 2021) Dark sector particles with small electric charge, or millicharge, (mCPs) may lead to a variety of diverse phenomena in particle physics, astrophysics, and cosmology. Assuming their possible existence, we investigate the accumulation and propagation of mCPs in matter, specifically inside the Earth. Even small values of millicharge lead to sizeable scattering cross sections on atoms, resulting in complete thermal- ization, and as a consequence, considerable build-up of number densities of mCPs, especially for the values of masses of GeV and higher when the evaporation becomes inhibited. Enhancement of mCP densities compared to their galactic abundance, that can be as big as 1014, leads to the possibility of new experimental probes for this model. The annihilation of pairs of mCPs will result in new signatures for the large volume detectors (such as Super-Kamiokande). Formation of bound states of negatively charged mCPs with nuclei can be observed by direct dark matter detection experiments. A unique probe of mCP can be developed using underground electrostatic accelerators that can directly accelerate mCPs above the experimental thresholds of direct dark matter detection experiments. DOI: 10.1103/PhysRevD.103.115031 I. INTRODUCTION millicharge dark matter or mCDM with their abundance set by the freeze-out or freeze-in. -
The Regulation of Fusion – a Practical and Innovation-Friendly Approach
The Regulation of Fusion – A Practical and Innovation-Friendly Approach February 2020 Amy C. Roma and Sachin S. Desai AUTHORS Amy C. Roma Sachin S. Desai Partner, Washington, D.C. Senior Associate, Washington, D.C. T +1 202 637 6831 T +1 202 637 3671 [email protected] [email protected] The authors want to sincerely thank the many stakeholders who provided feedback on this paper, and especially William Regan for his invaluable contributions and review of the technical discussion. TABLE OF CONTENTS I. EXECUTIVE SUMMARY 1 II. THE STATE OF FUSION INNOVATION 3 A) An Introduction to Fusion Energy 3 B) A Rapid Growth in Private-Sector Fusion Innovation 4 III. U.S. REGULATION OF ATOMIC ENERGY - NOT ONE SIZE FITS ALL 7 A) The Foundation of U.S. Nuclear Regulation - The Atomic Energy Act and the NRC 7 B) The Atomic Energy Act Embraces Different Regulations for Different Situations 7 1. NRC Frameworks for Different Safety Cases 8 2. Delegation of Regulatory Authority to States 9 IV. THE REGULATION OF FUSION - A PRACTICAL AND INNOVATION- FRIENDLY APPROACH 10 A) Fusion Regulation Comes to the Fore, Raising Key Questions 10 B) A Regulatory Proposal That Recognizes the Safety Case of Fusion and the Needs of Fusion Innovators 11 1. Near-Term: Regulation of Fusion Under the Part 30 Framework is Appropriate Through Development and Demonstration 11 2. Long-Term: The NRC Should Develop an Independent Regulatory Framework for Fusion at Commercial Scale, Not Adopt a Fission Framework 12 V. CONCLUSION 14 1 Hogan Lovells I. EXECUTIVE SUMMARY Fusion, the process that powers the Sun, has long been seen Most fusion technologies are already regulated by the NRC as the “holy grail” of energy production. -
Fundamental Physical Constants — Complete Listing Relative Std
From: http://physics.nist.gov/constants Fundamental Physical Constants — Complete Listing Relative std. Quantity Symbol Value Unit uncert. ur UNIVERSAL 1 speed of light in vacuum c; c0 299 792 458 m s− (exact) 7 2 magnetic constant µ0 4π 10− NA− × 7 2 = 12:566 370 614::: 10− NA− (exact) 2 × 12 1 electric constant 1/µ0c "0 8:854 187 817::: 10− F m− (exact) characteristic impedance × of vacuum µ / = µ c Z 376:730 313 461::: Ω (exact) p 0 0 0 0 Newtonian constant 11 3 1 2 3 of gravitation G 6:673(10) 10− m kg− s− 1:5 10− × 39 2 2 × 3 G=¯hc 6:707(10) 10− (GeV=c )− 1:5 10− × 34 × 8 Planck constant h 6:626 068 76(52) 10− J s 7:8 10− × 15 × 8 in eV s 4:135 667 27(16) 10− eV s 3:9 10− × 34 × 8 h=2π ¯h 1:054 571 596(82) 10− J s 7:8 10− × 16 × 8 in eV s 6:582 118 89(26) 10− eV s 3:9 10− × × 1=2 8 4 Planck mass (¯hc=G) mP 2:1767(16) 10− kg 7:5 10− 3 1=2 × 35 × 4 Planck length ¯h=mPc = (¯hG=c ) lP 1:6160(12) 10− m 7:5 10− 5 1=2 × 44 × 4 Planck time lP=c = (¯hG=c ) tP 5:3906(40) 10− s 7:5 10− × × ELECTROMAGNETIC 19 8 elementary charge e 1:602 176 462(63) 10− C 3:9 10− × 14 1 × 8 e=h 2:417 989 491(95) 10 AJ− 3:9 10− × × 15 8 magnetic flux quantum h=2e Φ0 2:067 833 636(81) 10− Wb 3:9 10− 2 × 5 × 9 conductance quantum 2e =h G0 7:748 091 696(28) 10− S 3:7 10− 1 × × 9 inverse of conductance quantum G0− 12 906:403 786(47) Ω 3:7 10− a 9 1 × 8 Josephson constant 2e=h KJ 483 597:898(19) 10 Hz V− 3:9 10− von Klitzing constantb × × 2 9 h=e = µ0c=2α RK 25 812:807 572(95) Ω 3:7 10− × 26 1 8 Bohr magneton e¯h=2me µB 927:400 899(37) 10− JT− 4:0 10− 1 × 5 1 × 9 in -
Neutron-Induced Damage Simulations: Beyond Defect Production Cross-Section, Displacement Per Atom and Iron-Based Metrics
EPJ Plus EPJ.org your physics journal Eur. Phys. J. Plus (2019) 134: 350 DOI 10.1140/epjp/i2019-12758-y Neutron-induced damage simulations: Beyond defect production cross-section, displacement per atom and iron-based metrics J.-Ch. Sublet et al. Eur. Phys. J. Plus (2019) 134: 350 THE EUROPEAN DOI 10.1140/epjp/i2019-12758-y PHYSICAL JOURNAL PLUS Review Neutron-induced damage simulations: Beyond defect production cross-section, displacement per atom and iron-based metrics J.-Ch. Sublet1,a, I.P. Bondarenko2,G.Bonny3, J.L. Conlin4, M.R. Gilbert5,L.R.Greenwood6, P.J. Griffin7, P. Helgesson8, Y. Iwamoto9, V.A. Khryachkov2, T.A. Khromyleva2, A.Yu. Konobeyev10, N. Lazarev11, L. Luneville12, F. Mota13, C.J. Ortiz13,D.Rochman14, S.P. Simakov10, D. Simeone12,H.Sjostrand8, D. Terentyev3, and R. Vila13 1 International Atomic Energy Agency, Wagramerstrasse 5, 1400 Vienna, Austria 2 State Atomic Energy Corporation ROSATOM, Institute for Physics and Power Engineering, Obninsk, Russia 3 Nuclear Materials Science Institute, SCK-CEN, Boeretang 200, B-2400 Mol, Belgium 4 Los Alamos National Laboratory, Los Alamos, NM, USA 5 United Kingdom Atomic Energy Authority, Culham Science Centre, Abingdon OX14 3DB, UK 6 Pacific Northwest National Laboratory, Richland, WA, USA 7 Sandia National Laboratories, Radiation and Electrical Science Center, Albuquerque, NM, USA 8 Uppsala University, Department of Physics and Astronomy, 751 20 Uppsala, Sweden 9 Japan Atomic Energy Agency, Nuclear Science and Engineering Center, Tokai, Ibaraki 319-1195, Japan 10 Institute for Neutron -
Arxiv:1707.07258V4 [Hep-Ph] 30 Mar 2020
I. INTRODCUTION The existence of dark matter is overwhelmingly supported by numerous cosmological and astrophysical observations on a wide range of scales. However, the nature of dark matter has not been revealed for almost a century except for its gravitational interactions. The identification of the nature of dark matter is one of the most important challenges of modern particle physics (see [1{3] for review). Among various candidates for dark matter, the weakly interacting massive particles (WIMPs) are the most extensively studied category of dark matter. The WIMPs couple to the standard model particles via interactions similar in strength to the weak nuclear force. Through the weak interaction, the WIMPs are thermally produced in the early uni- verse, and the relic density is set as they freeze out from the thermal bath [4]. The WIMPs are particularly attractive since the dark matter density does not depend on the details of the initial condition of the universe. The WIMPs are also highly motivated as they are interrelated to physics beyond the standard model such as supersymmetry (see e.g. [5]). The ambient WIMPs can be directly detected by searching for its scattering with the atomic nuclei [6]. Given a circular speed at around the Sun of 239 ± 5 km/s [7], the WIMPs recoil the nuclei elastically with a typical momentum transfer of qA ∼ 100 MeV for the target 1 nucleus mass of mN ∼ 100 GeV. The recoil signatures are detected through ionization, scintillation, and the production of heat in the detectors (see [8{10] for review). To date, for example, liquid xenon detectors such as LUX [11], PandaX-II [12], and XENON1T [13] have put stringent exclusion limits on the spin-independent WIMP-nucleon recoil cross section.