DOCSLIB.ORG

Beyond Scattering – What More Can Be Learned from Pulsed Kev Ion Beams?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Beyond Scattering – What More Can Be Learned from Pulsed Kev Ion Beams? Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1945 Beyond scattering – what more can be learned from pulsed keV ion beams? SVENJA LOHMANN ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-513-0964-4 UPPSALA urn:nbn:se:uu:diva-409892 2020 Dissertation presented at Uppsala University to be publicly examined in Polhelmsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, Friday, 12 June 2020 at 09:15 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Professor Andreas Wucher (University of Duisburg-Essen, Faculty of Physics). Abstract Lohmann, S. 2020. Beyond scattering – what more can be learned from pulsed keV ion beams? Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1945. 90 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0964-4. Interactions of energetic ions with matter govern processes as diverse as the influence of solar wind, hadron therapy for cancer treatment and plasma-wall interactions in fusion devices, and are used for controlled manipulation of materials properties as well as analytical methods. The scattering of ions from target nuclei and electrons does not only lead to energy deposition, but can induce the emission of different secondary particles including electrons, photons, sputtered target ions and neutrals as well as nuclear reaction products. In the medium-energy regime (ion energies between several ten to a few hundred keV), ions are expected to primarily interact with valence electrons. Dynamic electronic excitations are, however, not understood in full detail, and remain an active field of experimental and theoretical research. In addition, whereas scattered ions are employed for high-resolution depth profiling in medium energy ion scattering (MEIS), research on secondary particle emission in this regime is scarce. This thesis explores possibilities to experimentally study ion-solid interactions in the medium- energy regime beyond a backscattering approach. The capability for detection of electrons, photons and sputtered ions was integrated into the time-of-flight (ToF-) MEIS set-up at Uppsala University. Additionally, transmission of ions in combination with crystalline samples was employed to study impact-parameter dependent electronic excitations. In all cases, the use of pulsed ion beams with nanosecond pulse widths proves to be imperative for achieving energy measurements with sufficient resolution as well as low doses for non-destructive interactions even with sensitive samples. Trajectory-dependent energy loss of various ions in Si(100) was studied. For all ions heavier than protons, experimental evidence shows that, if close collisions are not suppressed by channelling, consequent charge-exchange events increase the mean charge state of the ion and heavily influence the experienced energy loss. Furthermore, measurements of electron emission are presented. For medium-energy ions, electrons emitted in forward direction from carbon foils exhibit energies between 10 and 400 eV. Scaling with ion velocity indicates binary collisions as the primary energy transfer mechanism. Detected photons also have energies of a few eV, i.e. on the order of typical valence transitions in solids. For photon emission, pronounced chemical matrix effects are observed. Finally, the sputtering process at medium energies was studied. Target bulk constituents exhibit similar behaviour as known from established methods at lower energies, i.e. sputtering by nuclear collision cascades. In contrast, the desorption of surface species seems to be governed by electronic energy transfer mechanisms. Keywords: Charge exchange, Deep UV photons, Electron emission, Silicon, Sputtering, TOF- MEIS Svenja Lohmann, Department of Physics and Astronomy, Applied Nuclear Physics, Box 516, Uppsala University, SE-751 20 Uppsala, Sweden. © Svenja Lohmann 2020 ISSN 1651-6214 ISBN 978-91-513-0964-4 urn:nbn:se:uu:diva-409892 (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-409892) List of Papers This thesis is based on the following papers, which are referred to in the text by their Roman numerals. I. Disparate energy scaling of trajectory-dependent electronic excita- tions for slow protons and He ions S. Lohmann, and D. Primetzhofer. Phys. Rev. Lett., 124: 096601. 2020. II. Trajectory-dependent electronic excitations by light and heavy ions around and below the Bohr velocity S. Lohmann, R. Holenák,ˇ and D. Primetzhofer. In manuscript form. III. Assessing electron emission induced by pulsed ion beams: a time-of- flight approach S. Lohmann, A. Niggas, V. Charnay, R. Holenák,ˇ and D. Primetzhofer. Manuscript submitted for publication. IV. Analysis of photon emission induced by light and heavy ions in time- of-flight medium energy ion scattering S. Lohmann, M. A. Sortica, V. Paneta, and D. Primetzhofer. Nucl. In- strum. Methods Phys. Res., Sect. B, 417: 75–8. 2018. V. Ion-induced particle desorption in time-of-flight medium energy ion scattering S. Lohmann, and D. Primetzhofer. Nucl. Instrum. Methods Phys. Res., Sect. B, 423: 22–26. 2018. Reprints were made with permission from the publishers. iii My contributions to the included papers: Paper I I participated in planning the study, conducted all experiments and analysed the data. I interpreted the results together with my supervisor and wrote the initial manuscript. Paper II I was involved in planning this study. I measured parts of the data and assisted with the remaining experiments. I did the analysis, interpreted the results to- gether with the other authors and wrote the manuscript. Paper III I was involved in planning the study and in making necessary changes to the set-up. I conducted the experiments together with co-authors. I anal- ysed all data and interpreted them together with the other authors. I wrote the manuscript. Paper IV I manufactured the Au samples and conducted the majority of experiments. I analysed the data, interpreted the results in discussion with the other authors and wrote the manuscript. Paper V I was involved in planning the experiments and implemented necessary ad- justments for secondary ion detection. I performed the measurements and analysed the data. I interpreted the results together with my supervisor and wrote the manuscript. iv Related publications with my authorship not included in this thesis: VI. Electronic energy-loss mechanisms for H, He, and Ne in TiN M. A. Sortica, V. Paneta, B. Bruckner, S. Lohmann, M. Hans, T. Nyberg, P. Bauer and D. Primetzhofer. Phys. Rev. A, 96(3): 032703. 2017. VII. On the Z1-dependence of electronic stopping in TiN M. A. Sortica, V. Paneta, B. Bruckner, S. Lohmann, T. Nyberg, P. Bauer, and D. Primetzhofer. Sci. Rep., 9(1): 176. 2019. VIII. A versatile time-of-flight medium-energy ion scattering setup using multiple delay-line detectors M. A. Sortica, M. K. Linnarsson, D. Wessman, S. Lohmann, and D. Primetzhofer. Nucl. Instrum. Methods Phys. Res., Sect. B, 463: 16–20. 2020. IX. Contrast modes in a 3D ion transmission approach at keV energies R. Holenák,ˇ S. Lohmann, and D. Primetzhofer. Manuscript submitted for publication. v My contributions to the non-included papers: Paper VI I conducted some of the experiments, contributed to the analysis and critically revised the manuscript. Paper VII I helped with some of the measurements and contributed to the analysis. I critically revised the manuscript. Paper VIII I was responsible for the development of transmission experiments and for the integration of mass spectrometry and electron detection into the set-up. I was also involved in improving in-situ sample cleaning methods. I revised the manuscript. Paper IX I was involved in planning this study and contributed the experimental data. I helped interpret the results and critically revised the manuscript. vi Contents List of Papers .................................................................................................... iii Abbreviations ..................................................................................................... x 1 Introduction .................................................................................................. 1 2 Ion-solid interactions ................................................................................... 5 2.1 Binary collisions ............................................................................... 5 2.2 Scattering in the solid: channelling and blocking .......................... 7 2.3 The role of electrons ........................................................................ 9 2.3.1 Screening ............................................................................ 9 2.3.2 Stopping models .............................................................. 10 2.3.3 Charge-exchange processes ............................................ 13 2.4 Ion-induced emission phenomena ................................................. 16 2.4.1 General concepts ............................................................. 16 2.4.2 Electron emission ............................................................ 16 2.4.3 Photon emission ............................................................... 19 2.4.4 Sputtering and desorption ............................................... 20 3 Experimental set-up and methods ............................................................ 23 3.1 Medium energy ion scattering ....................................................... 23 3.1.1 General set-up .................................................................
Load more

Recommended publications
  • 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]
  • Generation and Modeling of Radiation for Clinical and Research Applications Bishwambhar Sengupta Clemson University, [email protected]
    Clemson University TigerPrints All Dissertations Dissertations 8-2019 Generation and Modeling of Radiation for Clinical and Research Applications Bishwambhar Sengupta Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_dissertations Recommended Citation Sengupta, Bishwambhar, "Generation and Modeling of Radiation for Clinical and Research Applications" (2019). All Dissertations. 2440. https://tigerprints.clemson.edu/all_dissertations/2440 This Dissertation is brought to you for free and open access by the Dissertations at TigerPrints. It has been accepted for inclusion in All Dissertations by an authorized administrator of TigerPrints. For more information, please contact [email protected]. Generation and Modeling of Radiation for Clinical and Research Applications A Dissertation Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Physics by Bishwambhar Sengupta August 2019 Accepted by: Dr. Endre Takacs, Committee Chair Dr. Delphine Dean Dr. Brian Dean Dr. Jian He Abstract Cancer is one of the leading causes of death in todays world and also accounts for a major share of healthcare expenses for any country. Our research goals are to help create a device which has improved accuracy and treatment times that will alleviate the resource strain currently faced by the healthcare community and to shed some light on the elementary nature of the interaction between ionizing radiation and living cells. Stereotactic radiosurgery is the treatment of cases in intracranial locations using external radiation beams. There are several devices that can perform radiosurgery, but the Rotating Gamma System is relatively new and has not been extensively studied.
    [Show full text]
  • Interactions of Particles and Matter, with a View to Tracking
    Interactions of particles and matter, with a view to tracking 2nd EIROforum School on Instrumentation, May 15th-22nd 2011, EPN science campus, Grenoble The importance of interactions Particles can interact with matter they traverse according to their nature and energy, and according to the properties of the matter being traversed. These interactions blur the trajectory and cause energy loss, but ... they are the basis for tracking and identification. In this presentation, we review the mechanisms that are relevant to present particle physics experiments. Particles we©re interested in Common, long-lived particles that high- energy experiments track and identify: gauge bosons: leptons: e±, µ±, , e µ hadrons: p, n, , K, ... Most are subject to electro-magnetic interactions (), some interact through the strong force (gluons), a few only feel the weak force (W±, Z). No gravity ... [Drawings: Mark Alford (0- mesons, ½+ baryons), ETHZ (bottom)] Energies that concern us The physics of current experiments may play in the TeV-EeV energy range. But detection relies on processes from the particle energy down to the eV ! [Top: LHC, 3.5+3.5 TeV, Bottom: Auger Observatory, > EeV] Interactions of neutrinos Neutrino interactions with matter are exceedingly rare. Interactions coming in 2 kinds: W± exchange: ªcharged currentº Z exchange: ªneutral currentº Typical reactions: - e n p e + e p n e ( discovery: Reines and Cowan, 1956) - + ± (in the vicinity of a nucleus, W or Z) - - e e (neutral current discovery, 1973) First neutral current event First neutral current event, seen in + the Gargamelle bubble chamber: e - - + - e e e e - One candidate found in 360,000 e anti-neutrino events.
    [Show full text]
  • Bethe Formula
    Bethe formula The Bethe formula describes[1] the mean energy loss per distance travelled of swift charged particles (protons, alpha particles, atomic ions) traversing matter (or alternatively the stopping power of the material). For electrons the energy loss is slightly different due to their small mass (requiring relativistic corrections) and their indistinguishability, and since they suffer much larger losses by Bremsstrahlung, terms must be added to account for this. Fast charged particles moving through matter interact with the electrons of atoms in the material. The interaction excites or ionizes the atoms, leading to an energy loss of the traveling particle. The non-relativistic version was found by Hans Bethe in 1930; the relativistic version (shown below) was found by him in 1932.[2] The most probable energy loss differs from the mean energy loss and is described by the Landau-Vavilov distribution.[3] The Bethe formula is sometimes called "Bethe-Bloch formula", but this is misleading (see below). Contents The formula The mean excitation potential Corrections to the Bethe formula The problem of nomenclature See also References External links The formula For a particle with speed v, charge z (in multiples of the electron charge), and energy E, traveling a distance x into a target of electron number density n and mean excitation potential I, the relativistic version of the formula reads, in SI units:[2] (1) where c is the speed of light and ε0 the vacuum permittivity, , e and me the electron charge and rest mass respectively. Here, the electron density of the material can be calculated by where ρ is the density of the material, Z its atomic number, A its relative atomic mass, NA the Avogadro number and Mu the Molar mass constant.
    [Show full text]
  • Experiment 5 Energy Loss with Heavy Charged Particles (Alphas)
    Experiment 5 Energy Loss with Heavy Charged Particles (Alphas) Equipment Required • ULTRA™ Charged Particle Detector model BU-014-050-100 • C-29 BNC Tee Connector • 142A Preamplifier • ALPHA-PPS-115 (or 230) Portable Vacuum Pump Station • 4001A/4002D NIM Bin and Power Supply • TDS3032C Oscilloscope with bandwidth ≥150 MHz • 575A Spectroscopy Amplifier • AF-210-A1* consisting of 1 µCi of 210 Po. • 807 Vacuum Chamber • 01865-AB 2.5-micron Mylar 3" X 300' • 428 Detector Bias Supply • 01866-AB 3.6-micron Mylar 3" X 300' • 480 Pulser • 01867-AB 6.0-micron Mylar 3" X 300' • EASY-MCA-8K including a USB cable and MAESTRO software (other ORTEC • This experiment requires fabrication of Mylar film holders from cardboard or MCAs may be substituted) plastic for Mylar thicknesses from 2.5 to 25 microns in increments of 2.5 or • C-36-12 RG-59A/U 75 Coaxial Cable with SHV Plugs, 12-ft (3.7-m) length 3.6 microns. • C-24-1/2 RG-62A/U 93 Coaxial Cable with BNC Plugs, 0.5-ft. (15-cm) • Small, flat-blade screwdriver for tuning screwdriver-adjustable controls length • Personal Computer with USB port and Windows operating system • Two C-24-4 RG-62A/U 93 Coaxial Cables with BNC Plugs, 4-ft. (1.2-cm) • Access to a suitable printer for printing/plotting spectra acquired with length MAESTRO. • Two C-24-12 RG-62A/U 93 Coaxial Cables with BNC Plugs, 12-ft (3.7-m) length *Sources are available direct from supplier. See the ORTEC website at www.ortec-online.com/Service-Support/Library/Experiments-Radioactive-Source- Suppliers.aspx Purpose In this experiment the principle concern will be the rate of energy loss, dE/dx, and the range of an alpha particle as it passes through matter.
    [Show full text]
  • Passage of Particles Through Matter
    C4: Particle Physics Major Option Passage of Particles Through Matter Author: William Frass Lecturer: Dr. Roman Walczak Michaelmas 2009 1 Contents 1 Passage of charged particles through matter3 1.1 Energy loss by ionisation.....................................3 1.1.1 Energy loss per unit distance: the Bethe formula...................3 1.1.2 Observations on the Bethe formula...........................5 1.1.3 Behaviour of the Bethe formula as a function of velocity...............5 1.1.4 Particle ranges......................................7 1.1.5 Back-scattering and channelling.............................8 1.1.6 The possibility of particle identification........................9 1.1.7 Final energy dissipation.................................9 1.2 Energy loss by radiation: bremsstrahlung........................... 10 1.2.1 In the E-field of atomic nuclei.............................. 10 1.2.2 In the E-field of Z atomic electrons.......................... 10 1.2.3 Energy loss per unit distance and radiation lengths.................. 11 1.2.4 Particle ranges...................................... 11 1.3 Comparison between energy loss by ionisation and radiation................. 12 1.3.1 The dominant mechanism of energy loss........................ 12 1.3.2 Critical energy, EC .................................... 12 1.4 Energy loss by radiation: Cerenkovˇ radiation......................... 14 2 Passage of photons through matter 15 2.1 Absorption of electromagnetic radiation............................ 15 2.1.1 Linear attenuation coefficient, µ ...........................
    [Show full text]
  • Passage of Particles Through Matter 1
    27. Passage of particles through matter 1 27. PASSAGE OF PARTICLES THROUGH MATTER..................... 2 27.1.Notation................... 2 27.2. Electronic energy loss by heavy particles.................... 3 27.2.1. Moments and cross sections . 3 27.2.2. Stopping power at intermediate energies................... 4 27.2.3. Energy loss at low energies . 8 27.2.4.Densityeffect............... 10 27.2.5. Energetic knock-on electrons (δ rays)..................... 11 27.2.6. Restricted energy loss rates for relativistic ionizing particles . 11 27.2.7. Fluctuations in energy loss . 12 27.2.8. Energy loss in mixtures and compounds . 13 27.2.9.Ionizationyields.............. 14 27.3. Multiple scattering through small angles..................... 15 27.4. Photon and electron interactions in matter..................... 17 27.4.1. Radiation length . 17 27.4.2. Energy loss by electrons . 18 27.4.3.Criticalenergy.............. 22 27.4.4. Energy loss by photons . 24 27.4.5. Bremsstrahlung and pair production at very high energies . 26 27.4.6. Photonuclear and electronuclear interactions at still higher energies . 27 27.5. Electromagnetic cascades . 27 27.6. Muon energy loss at high energy . 30 27.7. Cherenkov and transition radiation . 32 C. Amsler et al.,PLB667, 1 (2008) and 2009 partial update for the 2010 edition (http://pdg.lbl.gov) February 2, 2010 15:55 2 27. Passage of particles through matter 27. PASSAGE OF PARTICLES THROUGH MATTER Revised January 2010 by H. Bichsel (University of Washington), D.E. Groom (LBNL), and S.R. Klein (LBNL). 27.1. Notation Table 27.1: Summary of variables used in this section.
    [Show full text]
  • 27. Passage of Particles Through Matter 1 27
    27. Passage of particles through matter 1 27. PASSAGE OF PARTICLES THROUGH MATTER Revised April 2002 by H. Bichsel (University of Washington), D.E. Groom (LBNL), and S.R. Klein (LBNL). 27.1. Notation Table 27.1: Summary of variables used in this section. The kinematic variables β and γ have their usual meanings. Symbol Definition Units or Value α Fine structure constant 1/137.035 999 11(46) e2 c ( /4π0 ~ ) M Incident particle mass MeV/c2 E Incident particle energy γMc2 MeV T Kinetic energy MeV mec2 Electron mass × c2 0.510 998 918(44) MeV re Classical electron radius 2.817 940 325(28) fm 2 2 e /4π0mec − NA Avogadro’s number 6.022 1415(10) × 1023 mol 1 ze Charge of incident particle Z Atomic number of absorber A Atomic mass of absorber g mol−1 2 2 −1 2 K/A 4πNAremec /A 0.307 075 MeV g cm forA=1gmol−1 I Mean excitation energy eV (Nota bene!) δ Density effect correction to ionization energyp loss ω . ρhZ/Ai (a) ~ p Plasmap energy 28 816 eV 2 ( 4πNere3 mec /α) − Nc Electron density (units of re) 3 wj Weight fraction of the jth element in a compound or mixture nj ∝ number of jth kind of atoms in a compound or mixture 2 −2 −1 −1 —4αre NA/A (716.408 g cm ) for A =1gmol −2 X0 Radiation length g cm Ec Critical energy for electrons MeV E µc Critical energyp for muons GeV Es Scale energy 4π/α mec2 21.2052 MeV − RM Moli`ere radius g cm 2 (a) For ρ in g cm−3.
    [Show full text]
  • A Calculation of Electron-Bremsstrahlung Produced in Thick Targets
    W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1968 A Calculation of Electron-Bremsstrahlung Produced in Thick Targets Chris Gross College of William & Mary - Arts & Sciences Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Physics Commons Recommended Citation Gross, Chris, "A Calculation of Electron-Bremsstrahlung Produced in Thick Targets" (1968). Dissertations, Theses, and Masters Projects. Paper 1539624655. https://dx.doi.org/doi:10.21220/s2-50rh-4m69 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. A CALCULATION OF ELECTRON- BREMSSTRAHUJNG PRODUCED IN THICK TARGETS A Thesis Presented to The Faculty of the Department of Physics The College of William and Mary in Vitginia In Partial Fulfillment of the Requirements for the Degree of Master of Arts By Chris Gross May 1968 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts Author Approved, May 1968 Herbert 0* Funsten, Ph.D. Robert E. Welsh, Ph.D. Q siaLlyI s%Jux Arden Sher, Ph.D. ii 410104 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts Author Approved, May 1968 Herbert 0* Funsten, Ph.D. Robert E. Welsh, Ph.D. Q s d L t y i Arden Sher, Ph.D. 11 ACKNOWLEDGEMENT The author wishes to express his gratitude to the National Aeronautics and Space Administration for the opportunity to write this thesis.
    [Show full text]
  • PINAKI SANKAR RAY, M.Sc. (CALCUTTA)
    THEORY OF ABSORFHON OF HIGH ENERGY (MeV-GeV) NUCLEI AND OF REHEAT FOR THERMONUCLEAR REACTIONS IN INERTIALLY CONFINED LASER COMPRESSED PLASMA PINAKI SANKAR RAY, M.Sc. (CALCUTTA) THESIS SUBMITTED FOR THE DEGREE OF DOCTOR of PHILOSOPHY IN THE FACULTY OF SCIENCE THE UNIVERSITY OF NEW SOUTH WALES AUGUST 1977 y 'IVERSITY OF N.S.W. 43303 2VAPR.78 LIBRARY riiwy1^ mm'**** (i) ACKNOWLEDGEMENT The author is deeply indebted to Professor Heinrich Hora, Head of the Department of Theoretical Physics, for suggesting the problem and supervising the research. He has introduced him to the subject of laser fusion, and above all his enthusiasm for work has been the author's greatest encouragement. (ii) ABSTRACT The theory of laser induced nuclear fusion reactions under inertial confinement has been investigated in this work. The special reactions treated numerically are the deuterium-tritium and the hydrogen-boron(11) fusion in plasma of densities corresponding to the solid state and higher. The energy gain has been calculated both with and without the incorporation of plasma heating due to the absorption of the MeV alphas released in the reactions. This reheat by the alphas is related to their range and the concept of the penetration length of energetic charged particles in plasma has been discussed from the point of view of the Fokker-Planck formalism. As a point of theoretical interest the process of soft photon emission during scattering as necessitated by quantum electrodynamics has also been incorporated in the Fokker-Planck method. In this case one does not need the Coulomb logarithm to avoid the divergence of small angle scattering.
    [Show full text]
  • Particle Physics Instrumentation
    Proceedings of the 2014 Asia–Europe–Pacific School of High-Energy Physics, Puri, India, 4–17 November 2014, edited by M. Mulders and R. Godbole, CERN Yellow Reports: School Proceedings, Vol. 2/2017, CERN-2017-005-SP (CERN, Geneva, 2017) Particle Physics Instrumentation I. Wingerter-Seez LAPP, CNRS, Paris, France, and Université Savoie Mont Blanc, Chambéry, France Abstract This reports summarizes the three lectures on particle physics instrumentation given during the AEPSHEP school in November 2014 at Puri-India. The lec- tures were intended to give an overview of the interaction of particles with matter and basic particle detection principles in the context of large detector systems like the Large Hadron Collider. Keywords Lectures; instrumentation; particle physics; detector; energy loss; multiple scattering. 1 Introduction This report gives a very brief overview of the basis of particle detection and identification in the context of high-energy physics (HEP). It is organized into three main parts. A very simplified description of the interaction of particles with matter is given in Sections 2 and 3; an overview of the development of electromagnetic (EM) and hadronic showers is given in Section 4. Sections 5 and 6 are devoted to the principle of operation of gas- and solid-state detectors and calorimetry. Finally, Sections 7 and 8 give a rapid overview of the HEP detectors and a few examples. 2 Basics of particle detection Experimental particle physics is based on high precision detectors and methods. Particle detection ex- ploits the characteristic interaction with matter of a few well-known particles. The Standard Model of particle physics is based on 12 elementary fermion particles (six leptons, six quarks), four types of spin-1 bosons (photon, W, Z, and gluon) and the spin-0 Higgs boson.
    [Show full text]
  • Radiation Interactions with Matter: Energy Deposition
    22.55 “Principles of Radiation Interactions” Radiation Interactions with Matter: Energy Deposition Biological effects are the end product of a long series of phenomena, set in motion by the passage of radiation through the medium. [Image removed due to copyright considerations] Radiation Interactions: HCP Page 1 of 20 22.55 “Principles of Radiation Interactions” Interactions of Heavy Charged Particles Energy-Loss Mechanisms • The basic mechanism for the slowing down of a moving charged particle is Coulombic interactions between the particle and electrons in the medium. This is common to all charged particles • A heavy charged particle traversing matter loses energy primarily through the ionization and excitation of atoms. • The moving charged particle exerts electromagnetic forces on atomic electrons and imparts energy to them. The energy transferred may be sufficient to knock an electron out of an atom and thus ionize it, or it may leave the atom in an excited, nonionized state. • A heavy charged particle can transfer only a small fraction of its energy in a single electronic collision. Its deflection in the collision is negligible. • All heavy charged particles travel essentially straight paths in matter. [Image removed due to copyright considerations] [Tubiana, 1990] Radiation Interactions: HCP Page 2 of 20 22.55 “Principles of Radiation Interactions” Maximum Energy Transfer in a Single Collision The maximum energy transfer occurs if the collision is head-on. [Image removed due to copyright considerations] Assumptions: • The particle moves rapidly compared with the electron. • For maximum energy transfer, the collision is head-on. • The energy transferred is large compared with the binding energy of the electron in the atom.
    [Show full text]