DOCSLIB.ORG

Sub Atomic Particles and Phy 009 Sub Atomic Particles and Developments in Cern Developments in Cern

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Sub Atomic Particles and Phy 009 Sub Atomic Particles and Developments in Cern Developments in Cern 1) Mahantesh L Chikkadesai 2) Ramakrishna R Pujari [email protected] [email protected] Mobile no: +919480780580 Mobile no: +917411812551 Phy 009 Sub atomic particles and Phy 009 Sub atomic particles and developments in cern developments in cern Electrical and Electronics Electrical and Electronics KLS’s Vishwanathrao deshpande rural KLS’s Vishwanathrao deshpande rural institute of technology institute of technology Haliyal, Uttar Kannada Haliyal, Uttar Kannada SUB ATOMIC PARTICLES AND DEVELOPMENTS IN CERN Abstract-This paper reviews past and present cosmic rays. Anderson discovered their existence; developments of sub atomic particles in CERN. It High-energy subato mic particles in the form gives the information of sub atomic particles and of cosmic rays continually rain down on the Earth’s deals with basic concepts of particle physics, atmosphere from outer space. classification and characteristics of them. Sub atomic More-unusual subatomic particles —such as particles also called elementary particle, any of various self-contained units of matter or energy that the positron, the antimatter counterpart of the are the fundamental constituents of all matter. All of electron—have been detected and characterized the known matter in the universe today is made up of in cosmic-ray interactions in the Earth’s elementary particles (quarks and leptons), held atmosphere. together by fundamental forces which are Quarks and electrons are some of the elementary represente d by the exchange of particles known as particles we study at CERN and in other gauge bosons. Standard model is the theory that laboratories. But physicists have found more of describes the role of these fundamental particles and these elementary particles in various experiments. interactions between them, this is briefly reviewed Our best understanding of how these particles and and this standard model with its salient features described. T o understand how the universe evolved three of the forces are related to each other is we really need to understand the behaviour of encapsulated in the Standard Model of particle elementary particles: the quarks, leptons and gauge physics. Developed in the early 1970s, it has bosons. Since from 1954 several important successfully explained almost all experimental achievements in particle physics have been made results and precisely predicted a wide variety of during experiments at CERN, th ey have discovered phenomena. Over time and through many many particles. In this paper, several results of those experiments, the Standard Model has become experiments are described. established as a well-tested physics theory. Keywords: Elementary particles, Large Hadron Collider, fundamental interactions, gauge boson, Fermi lab. I. INTRODUCTION The theories and discoveries of tho usands of physicists since the 1930s have resulted in a remarkable insight into the fundamental structure of matter: everything in the universe is found to be made from a few basic building blocks called fundamental particles. Small particles in the hierarchy of the universe were discovered and researched: these are commonly molecules , that are constructed of atoms , that in turn consist of subatomic particles, Thomson ha d discovered the first subatomic particle. A subatomic particle is a particle smaller than an atom: it may be elementary or composite. These particles include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually c omposite particles, made up of quarks), as well as other particles such as photons and neutrinos which are produced copiously in the sun. The concept of spin is now recognized as an intrinsic property of all subatomic particles. However, most of the particles that have been discovered and studied are not encountered under normal earth conditions; they are produced in Fig.1 evolution of sub atomic particles II. CERN • The ALPHA experiment is a successor of an earlier antimatter experiment. The European Organization for Nuclear Research e) AMS: known as CERN, whose purpose is to operate the • The Alpha Magnetic Spectrometer looks world's largest particle physics laboratory. for dark matter, antimatter and missing Established in 29 September 1954, the organization matter from a module on the International is based in the northwest suburbs of Geneva on the Space Station. Franco–Swiss border, and has twenty European • The Alpha Magnetic Spectrometer (AMS- member states. 02) is a particle-physics detector that looks CERN's main function is to provide the particle for dark matter, antimatter and missing accelerators and other infrastructure needed for matter from a module attached to the high-energy physics research. It is also the outside of the International Space Station birthplace of the World Wide Web. (ISS). It also performs precision measurements of cosmic rays. A. Experiments at CERN: f) ASACUSA: a) ACE: • The Atomic Spectroscopy And Collisions • The Antiproton Cell Experiment (ACE) Using Slow Antiprotons (ASACUSA) started in 2003. It aims to assess fully the experiment studies the fundamental effectiveness and suitability of antiprotons symmetries between matter and antimatter for cancer therapy. • by precision spectroscopy of atoms ACE brings together an international team containing an antiproton (the antimatter of physicists, biologists and medics to equivalent of the proton). The experiments study the biological effects of antiprotons. focused in particular on hybrid atoms • ACE is an excellent example of how (antiprotonic helium), ASACUSA research in particle physics can bring compares matter and antimatter using innovative solutions with potential atoms of antiprotonic helium and medical benefits. antihydrogen, and studies the properties of b) AEGIS: matter-antimatter collisions. • The primary scientific goal of the Anti g) ATLAS: hydrogen Experiment: Gravity, • ATLAS is one of two general-purpose Interferometry, Spectroscopy (AEGIS) is detectors at the Large Hadron Collider the direct measurement of the Earth's (LHC). It investigates a wide range of gravitational acceleration, on physics, from the search for the Higgs antihydrogen. boson to extra dimensions and particles • AEGIS uses a beam of antiprotons from that could make up matter. From a cavern the Antiproton Decelerator to measure the 100 metres below a small Swiss village, value of Earth’s gravitational acceleration. the 7000-tonne ATLAS detector is The AEGIS experiment will represent the probing for fundamental particles. first direct measurement of a gravitational h) ATRAP: effect on an antimatter system. • ATRAP compares hydrogen atoms with their antimatter equivalents - antihydrogen atoms. The Antihydrogen trap (ATRAP) is an experiment to compare hydrogen atoms c) ALICE: with their antimatter equivalents – • ALICE detects quark-gluon plasma, a antihydrogen atoms. In 2002, ATRAP state of matter thought to have formed just provided the first glimpse inside after the big bang. antihydrogen atoms after researchers • ALICE (A Large Ion Collider Experiment) successfully created and measured a large is a heavy-ion detector on the Large number of them. ATRAP was the first Hadron Collider (LHC) ring. It is designed experiment to use cold positrons to cool to study the physics of strongly interacting antiprotons. matter at extreme energy densities, where i) AWAKE: a phase of matter called quark-gluon • AWAKE explores the use of plasma to plasma forms. accelerate particles to high energies over d) ALPHA: short distances. • ALPHA makes, captures and studies j) CAST: atoms of antihydrogen and compares them • The CERN Axion Solar Telescope with hydrogen atoms. (CAST) is an experiment to search for hypothetical particles called "axions". These have been proposed by some theoretical physicists to explain why and neutrons that form the nuclei of there is a subtle difference between matter ordinary atoms. and antimatter in processes involving the • A collaboration of CERN physicists are weak force, but not the strong force. If studying the decay of unstable “pionium axions exist, they could be found in the atoms” to gain insight into the strong centre of the Sun and they could also force. make up invisible dark matter. o) ISOLDE: • Hypothetical particles called axions could • ISOLDE studies the properties of atomic explain differences between matter and nuclei, with further applications in antimatter - and we may find them at the fundamental studies, astrophysics, centre of the Sun. material and life sciences The Isotope k) CLOUD: mass Separator On-Line facility • The Cosmics Leaving Outdoor Droplets (ISOLDE) is a unique source of low- (CLOUD) experiment uses a special cloud energy beams of radioactive nuclides, chamber to study the possible link those with too many or too few neutrons between galactic cosmic rays and cloud to be stable. It permits the study of the formation. Based at the Proton vast territory of atomic nuclei, including Synchrotron (PS) at CERN, this is the first the most exotic species. time a high-energy physics accelerator has p) LHCb: been used to study atmospheric and • The LHCb experiment will shed light on climate science. The results should why we live in a universe that appears to contribute much to our fundamental be composed almost entirely of matter, but understanding of aerosols and clouds, and no antimatter. their affect on climate. q) LHCf: • Could there be a link between galactic • The LHCf experiment uses particles cosmic rays and cloud formation? An thrown forward by LHC collisions
Load more

Recommended publications
  • CERN Courier–Digital Edition
    CERNMarch/April 2021 cerncourier.com COURIERReporting on international high-energy physics WELCOME CERN Courier – digital edition Welcome to the digital edition of the March/April 2021 issue of CERN Courier. Hadron colliders have contributed to a golden era of discovery in high-energy physics, hosting experiments that have enabled physicists to unearth the cornerstones of the Standard Model. This success story began 50 years ago with CERN’s Intersecting Storage Rings (featured on the cover of this issue) and culminated in the Large Hadron Collider (p38) – which has spawned thousands of papers in its first 10 years of operations alone (p47). It also bodes well for a potential future circular collider at CERN operating at a centre-of-mass energy of at least 100 TeV, a feasibility study for which is now in full swing. Even hadron colliders have their limits, however. To explore possible new physics at the highest energy scales, physicists are mounting a series of experiments to search for very weakly interacting “slim” particles that arise from extensions in the Standard Model (p25). Also celebrating a golden anniversary this year is the Institute for Nuclear Research in Moscow (p33), while, elsewhere in this issue: quantum sensors HADRON COLLIDERS target gravitational waves (p10); X-rays go behind the scenes of supernova 50 years of discovery 1987A (p12); a high-performance computing collaboration forms to handle the big-physics data onslaught (p22); Steven Weinberg talks about his latest work (p51); and much more. To sign up to the new-issue alert, please visit: http://comms.iop.org/k/iop/cerncourier To subscribe to the magazine, please visit: https://cerncourier.com/p/about-cern-courier EDITOR: MATTHEW CHALMERS, CERN DIGITAL EDITION CREATED BY IOP PUBLISHING ATLAS spots rare Higgs decay Weinberg on effective field theory Hunting for WISPs CCMarApr21_Cover_v1.indd 1 12/02/2021 09:24 CERNCOURIER www.
    [Show full text]
  • Mesons Modeled Using Only Electrons and Positrons with Relativistic Onium Theory Ray Fleming [email protected]
    All mesons modeled using only electrons and positrons with relativistic onium theory Ray Fleming [email protected] All mesons were investigated to determine if they can be modeled with the onium model discovered by Milne, Feynman, and Sternglass with only electrons and positrons. They discovered the relativistic positronium solution has the mass of a neutral pion and the relativistic onium mass increases in steps of me/α and me/2α per particle which is consistent with known mass quantization. Any pair of particles or resonances can orbit relativistically and particles and resonances can collocate to form increasingly complex resonances. Pions are positronium, kaons are pionium, D mesons are kaonium, and B mesons are Donium in the onium model. Baryons, which are addressed in another paper, have a non-relativistic nucleon combined with mesons. The results of this meson analysis shows that the compo- sition, charge, and mass of all mesons can be accurately modeled. Of the 220 mesons mod- eled, 170 mass estimates are within 5 MeV/c2 and masses of 111 of 121 D, B, charmonium, and bottomonium mesons are estimated to within 0.2% relative error. Since all mesons can be modeled using only electrons and positrons, quarks and quark theory are unnecessary. 1. Introduction 2. Method This paper is a report on an investigation to find Sternglass and Browne realized that a neutral pion whether mesons can be modeled as combinations of (π0), as a relativistic electron-positron pair, can orbit a only electrons and positrons using onium theory. A non-relativistic particle or resonance in what Browne companion paper on baryons is also available.
    [Show full text]
  • The Muon G-2 Discrepancy: Errors Or New Physics?
    The muon g-2 discrepancy: errors or new physics? † M. Passera∗, W. J. Marciano and A. Sirlin∗∗ ∗Istituto Nazionale Fisica Nucleare, Sezione di Padova, I-35131, Padova, Italy †Brookhaven National Laboratory, Upton, New York 11973, USA ∗∗Department of Physics, New York University, 10003 New York NY, USA Abstract. After a brief review of the muon g 2 status, we discuss hypothetical errors in the Standard Model prediction that could explain the present discrepancy with the− experimental value. None of them looks likely. In particular, an hypothetical + increase of the hadroproduction cross section in low-energy e e− collisions could bridge the muon g 2 discrepancy, but is shown to be unlikely in view of current experimental error estimates. If, nonetheless, this turns out to− be the explanation of the discrepancy, then the 95% CL upper bound on the Higgs boson mass is reduced to about 130 GeV which, in conjunction with the experimental 114.4 GeV 95% CL lower bound, leaves a narrow window for the mass of this fundamental particle. Keywords: Muon anomalous magnetic moment, Standard Model Higgs boson PACS: 13.40.Em, 14.60.Ef, 12.15.Lk, 14.80.Bn SM 11 INTRODUCTION aµ = 116591778(61) 10− . The difference with the EXP× 11 experimental value aµ = 116592080(63) 10− [1] The anomalousmagnetic momentof the muon, aµ ,isone EXP SM 11 × is ∆aµ = aµ aµ =+302(88) 10− , i.e., 3.4σ (all of the most interesting observables in particle physics. errors were added− in quadrature).× Similar discrepan- Indeed, as each sector of the Standard Model (SM) con- HLO cies are found employing the aµ values reported in tributes in a significant way to its theoretical prediction, Refs.
    [Show full text]
  • Very Forward Photon Production in Proton-Proton Collisions Measured by the Lhcf Experiment at the Large Hadron Collider
    Very forward photon production in proton-proton collisions measured by the LHCf experiment at the Large Hadron Collider Author: Alessio Tiberio Supervisor: Lorenzo Bonechi The LHC-forward (LHCf) experiment, situated at the LHC accelerator, has measured neutral particles production in a very forward region (pseudo-rapidity η > 8:4) in proton-proton and proton- lead collisions. The main purpose of the LHCf experiment is to test hadronic interaction models used in ground based cosmic rays experiments to simulate cosmic rays induced air-showers in the Earth's atmosphere. Highest energy cosmic rays can only be detected from secondary particles which are produced by the interaction of the primary particle with nuclei of the atmosphere. Studying the development of air showers, it is possible to reconstruct the type and kinematic parameters of primary particle. For this reason, Monte Carlo (MC) simulations with accurate hadronic interaction models are needed to reproduce the development of air-showers. Since the energy flow of secondary particles is concentrated in the forward direction, measurements of particle production at high pseudo-rapidity (i.e. small angles) are very important. Furthermore, soft QCD interactions (non perturbative regime) dominates in the very forward region and MC simulations of air showers are based on phenomenological model, so inputs from experimental data are crucial. The experiment is composed by two independent detectors (Arm1 and Arm2 ) located at 140 m from the ATLAS's interaction point (IP1) on opposite sides [1]. Detectors are placed inside the Target Neutral Absorber (TAN), where the beam pipe from IP1 turns into two separates tubes: the position between the two beam pipes allows to measure particles produced at zero degrees.
    [Show full text]
  • The Moedal Experiment at the LHC. Searching Beyond the Standard
    126 EPJ Web of Conferences , 02024 (2016) DOI: 10.1051/epjconf/201612602024 ICNFP 2015 The MoEDAL experiment at the LHC Searching beyond the standard model James L. Pinfold (for the MoEDAL Collaboration)1,a 1 University of Alberta, Physics Department, Edmonton, Alberta T6G 0V1, Canada Abstract. MoEDAL is a pioneering experiment designed to search for highly ionizing avatars of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles. Its groundbreaking physics program defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensions or new symmetries; what is the mechanism for the generation of mass; does magnetic charge exist; what is the nature of dark matter; and, how did the big-bang develop. MoEDAL’s purpose is to meet such far-reaching challenges at the frontier of the field. The innovative MoEDAL detector employs unconventional methodologies tuned to the prospect of discovery physics. The largely passive MoEDAL detector, deployed at Point 8 on the LHC ring, has a dual nature. First, it acts like a giant camera, comprised of nuclear track detectors - analyzed offline by ultra fast scanning microscopes - sensitive only to new physics. Second, it is uniquely able to trap the particle messengers of physics beyond the Standard Model for further study. MoEDAL’s radiation environment is monitored by a state-of-the-art real-time TimePix pixel detector array. A new MoEDAL sub-detector to extend MoEDAL’s reach to millicharged, minimally ionizing, particles (MMIPs) is under study Finally we shall describe the next step for MoEDAL called Cosmic MoEDAL, where we define a very large high altitude array to take the search for highly ionizing avatars of new physics to higher masses that are available from the cosmos.
    [Show full text]
  • REPORTS on RESEARCH PL9800669 6.1 the NA48
    114 Annual Report 1996 I REPORTS ON RESEARCH PL9800669 6.1 The NA48 experiment on direct CP violation by A.Chlopik, Z.Guzik, J.Nassalski, E.Rondio, M.Szleper and W.WisIicki The NA48 experiment [1] was built and tested on the kaon beam at CERN. It aims to measure the effect of direct violation of the combined CP transformation in two-pion decays of neutral kaons with precision of 0.1 permille. To perform such a measurement beams of the long-lived and short-lived Ks are produced which decay in the common region of phase space. Decays of both kaons into charged and neutral pions are measured simultaneously. The Warsaw group contributed to the electronics of the data acquisition system, to the offline software and took part in the data taking during test runs in June and September 1996. The hardware contribution of the group consisted of design, prototype manufacturing, testing and production supervision of the data acquisition blocks: RIO Fiber Optics Links, Cluster Interconnectors and Clock Fanouts. These elements are described in a separate note of this report. We worked on the following software related issues: (i) reconstruction of data and Monte Carlo in the magnetic spectrometer consisting of four drift chambers, the bending magnet and the trigger hodoscope. Energy and momentum resolution and background sources were carefully studied, (ii) decoding and undecoding of the liquid kryptonium calorimeter data. This part of the equipment is crucial for the measurement of neutral decays, (iii) correlated Monte Carlo to use the same events to simulate KL and K^ decays and thus speed up simulation considerably.
    [Show full text]
  • EPS-HEP 2017 Report of Contributions
    EPS-HEP 2017 Report of Contributions https://indico.cern.ch/e/epshep2017 EPS-HEP 2017 / Report of Contributions Theory overview on FCNC B-decays Contribution ID: 10 Type: Parallel Talk Theory overview on FCNC B-decays Thursday, 6 July 2017 09:00 (30 minutes) LHCb experiment at CERN has recently reported a set of measurements on lepton flavour univer- sality in b to s transitions showing a departure from the Standard Model predictions. I will review the main ideas recently put forward to make sense out of these intriguing hints. Focusing on the new physics explanation, I will discuss the correlated signals expected in other low- and high- energy observables, that could help clarify the mysterious signal. Experimental Collaboration Primary author: GRELJO, Admir (University of Zurich) Presenter: GRELJO, Admir (University of Zurich) Session Classification: Flavour and symmetries Track Classification: Flavour Physics and Fundamental Symmetries October 6, 2021 Page 1 EPS-HEP 2017 / Report of Contributions Charm Quark Mass with Calibrate … Contribution ID: 11 Type: Parallel Talk Charm Quark Mass with Calibrated Uncertainty Friday, 7 July 2017 12:35 (13 minutes) We determine the charm quark mass mc(mc) from QCD sum rules of moments of the vector cur- rent correlator calculated in perturbative QCD. Only experimental data for the charm resonances below the continuum threshold are needed in our approach, while the continuum contribution is determined by requiring self-consistency between various sum rules, including the one for the ze- roth moment. Existing data from the continuum region can then be used to bound the theoretical error. Our result is mc(mc) = 1272 ± 8 MeV for αs(MZ ) = 0:1182.
    [Show full text]
  • Particle Physics
    If you would like to register to receive Fascination automatically ISSUE 11 please visit www.stfc.ac.uk/fascination News from the Cover image: A proton collision at the ATLAS experiment which produced a microscopic-black-hole. Credit: CERN Science and Technology particle Facilities Council Exploring & Understanding Science physics special CONTENTS Benefits of particle physics LHC leads the way on new technology Higgs - The story so far Higgs Boson dominated the news media for two days LHC on tour in the UK Using the very large to look for the extremely small How did the Universe begin? What are we made of? Why are all world class. It represents amazing value for the amount does matter behave the way it does? These are questions of added benefit we get from what is at heart a fundamental that particle physics can answer. Particle physics is an ideal science project. With the recent breakthrough discovery of a showcase for STFC’s work – a subject where the research, the Higgs-like particle, this edition is focussing on particle physics resultant innovation and the inspirational value of the science and why it matters to the UK. The benefits of particle physics to you and everyone you know nature of matter, the so called known unknowns, and in the process uncover new questions we have yet to answer. It’s a compellingly difficult search that pushes our understanding of matter beyond the limits of what was previously possible. But the search is expensive, times are tough and costs need to be justified, so the secondary benefits from the research are often just as important.
    [Show full text]
  • Detection of Cosmic Rays at the LHC Detection of Cosmic Rays at the LHC
    Particle and Astroparticle Physics at the Large Hadron Collider --Hadronic Interactions-- Albert De Roeck CERN, Geneva, Switzerland Antwerp University Belgium UC-Davis California USA NTU, Singapore November 15th 2019 Outline • Introduction on the LHC and LHC physics program • LHC results for Astroparticle physics • Measurements of event characteristics at 13 TeV • Forward measurements • Cosmic ray measurements • LHC and light ions? • Summary The LHC Machine and Experiments MoEDAL LHCf FASER totem CM energy → Run-1: (2010-2012) 7/8 TeV Run-2: (2015-2018) 13 TeV -> Now 8 experiments Run-2 starts proton-proton Run-2 finished 24/10/18 6:00am 2018 2010-2012: Run-1 at 7/8 TeV CM energy Collected ~ 27 fb-1 2015-2018: Run-2 at 13 TeV CM Energy Collected ~ 140 fb-1 2021-2023/24 : Run-3 Expect ⇨ 14 TeV CM Energy and ~ 200/300 fb-1 The LHC is also a Heavy Ion Collider ALICE Data taking during the HI run • All experiments take AA or pA data (except TOTEM) Expected for Run-3: in addition short pO and OO runs ⇨ pO certainly of interest for Cosmic Ray Physics Community! 4 10 years of LHC Operation • LHC: 7 TeV in March 2010 ->The highest energy in the lab! • LHC @ 13 TeV from 2015 onwards March 30 2010 …waiting.. • Most important highlight so far: …since 4:00 am The discovery of a Higgs boson • Many results on Standard Model process measurements, QCD and particle production, top-physics, b-physics, heavy ion physics, searches, Higgs physics • Waiting for the next discovery… -> Searches beyond the Standard Model 12:58 7 TeV collisions!!! New Physics Hunters
    [Show full text]
  • Arxiv:2009.05616V2 [Hep-Ph] 18 Oct 2020 ± ± Bution from the Decays K → Π A2π (Considered in [1]) 2 0 0 Mrα Followed by the Decay A2π → Π Π [7]
    Possible manifestation of the 2p pionium in particle physics processes Peter Lichard Institute of Physics and Research Centre for Computational Physics and Data Processing, Silesian University in Opava, 746 01 Opava, Czech Republic and Institute of Experimental and Applied Physics, Czech Technical University in Prague, 128 00 Prague, Czech Republic 0 We suggest a few particle physics processes in which excited 2p pionium A2π may be observed. They include the e+e− ! π+π− annihilation, the V 0 ! π0`+`− and K± ! π±`+`− (` = e; µ) decays, and the photoproduction of two neutral pions from nucleons. We analyze available exper- imental data and find that they, in some cases, indicate the presence of 2p pionium, but do not provide definite proof. I. INTRODUCTION that its quantum numbers J PC = 1−− prevent it from decaying into the positive C-parity π0π0 and γγ states. The first thoughts about an atom composed of a pos- It must first undergo the 2p!1s transition to the ground state. The mean lifetime of 2p pionium itive pion and a negative pion (pionium, or A2π in the present-day notation) appeared almost sixty years ago. τ = 0:45+1:08 × 10−11 s: (1) Uretsky and Palfrey [1] assumed its existence and ana- 2p −0:30 lyzed the possibilities of detecting it in the photoproduc- is close to the value which comes for the π+π− atom tion off hydrogen target. Up to this time, such a process assuming a pure Coulomb interaction [8]. After reaching has not been observed. They also hypothesized about the 0 0 the 1s state, a decay to two π s quickly follows: A2π ! possibility of decay K+ ! π+A , which has recently 0 0 2π A2π + γ ! π π γ.
    [Show full text]
  • 6.2 Transition Radiation
    Contents I General introduction 9 1Preamble 11 2 Relevant publications 15 3 A first look at the formation length 21 4 Formation length 23 4.1Classicalformationlength..................... 24 4.1.1 A reduced wavelength distance from the electron to the photon ........................... 25 4.1.2 Ignorance of the exact location of emission . ....... 25 4.1.3 ‘Semi-bare’ electron . ................... 26 4.1.4 Field line picture of radiation . ............... 26 4.2Quantumformationlength..................... 28 II Interactions in amorphous targets 31 5 Bremsstrahlung 33 5.1Incoherentbremsstrahlung..................... 33 5.2Genericexperimentalsetup..................... 35 5.2.1 Detectors employed . ................... 35 5.3Expandedexperimentalsetup.................... 39 6 Landau-Pomeranchuk-Migdal (LPM) effect 47 6.1 Formation length and LPM effect.................. 48 6.2 Transition radiation . ....................... 52 6.3 Dielectric suppression - the Ter-Mikaelian effect.......... 54 6.4CERNLPMExperiment...................... 55 6.5Resultsanddiscussion....................... 55 3 4 CONTENTS 6.5.1 Determination of ELPM ................... 56 6.5.2 Suppression and possible compensation . ........ 59 7 Very thin targets 61 7.1Theory................................ 62 7.1.1 Multiple scattering dominated transition radiation . .... 62 7.2MSDTRExperiment........................ 63 7.3Results................................ 64 8 Ternovskii-Shul’ga-Fomin (TSF) effect 67 8.1Theory................................ 67 8.1.1 Logarithmic thickness dependence
    [Show full text]
  • Atmospheric Nucleation and Growth in the CLOUD Experiment at CERN Jasper Kirkby and CLOUD Collaboration
    Atmospheric nucleation and growth in the CLOUD experiment at CERN Jasper Kirkby and CLOUD Collaboration Citation: AIP Conference Proceedings 1527, 278 (2013); doi: 10.1063/1.4803258 View online: http://dx.doi.org/10.1063/1.4803258 View Table of Contents: http://scitation.aip.org/content/aip/proceeding/aipcp/1527?ver=pdfcov Published by the AIP Publishing Articles you may be interested in Multi-species nucleation rates in CLOUD AIP Conf. Proc. 1527, 326 (2013); 10.1063/1.4803269 Ternary H 2 SO 4 - H 2 O - NH 3 neutral and charged nucleation rates for a wide range of atmospheric conditions AIP Conf. Proc. 1527, 310 (2013); 10.1063/1.4803265 Observations and models of particle nucleation near cloud outflows AIP Conf. Proc. 534, 831 (2000); 10.1063/1.1361988 Application of nucleation theories to atmospheric aerosol formation AIP Conf. Proc. 534, 711 (2000); 10.1063/1.1361961 Laboratory studies of ice nucleation in sulfate particles: Implications for cirrus clouds AIP Conf. Proc. 534, 471 (2000); 10.1063/1.1361909 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP: 131.215.225.131 On: Tue, 19 Apr 2016 20:27:43 Atmospheric Nucleation and Growth in the CLOUD Experiment at CERN Jasper Kirkbya and the CLOUD collaborationb aCERN, CH-1211 Geneva, Switzerland b Aerodyne Research Inc., Billerica, Massachusetts 01821, USA California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, California 91125, USA Carnegie Mellon University, Dep. of Chemical
    [Show full text]