rpp2009-rev-passage-particles-matter

rpp2009-rev-passage-particles-matter - 27. Passage of...

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27. Passage of particles through matter 1 27. PASSAGE OF PARTICLES THROUGH MATTER. .................... 2 2 7 . 1 .N o t a t i o n ................... 2 27.2. Electronic energy loss by heavy p a r t i c l e s .................... 3 27.2.1. Moments and cross sections . . . . . . . . 3 27.2.2. Stopping power at intermediate e n e r g i e s ................... 4 27.2.3. Energy loss at low energies . . . . . . . . . 8 2 7 . 2 . 4 .D e n s i t ye f e c t............... 1 0 27.2.5. Energetic knock-on electrons ( δ r a y s )..................... 1 1 27.2.6. Restricted energy loss rates ±or relativistic ionizing particles . . . . . . . . . . 11 27.2.7. Fluctuations in energy loss . . . . . . . . . 12 27.2.8. Energy loss in mixtures and compounds . . . . . . . . . . . . . . . . . . 13 2 7 . 2 . 9 .I o n i z a t i o ny i e l d s.............. 1 4 27.3. Multiple scattering through small a n g l e s ..................... 1 5 27.4. Photon and electron interactions in m a t t e r ..................... 1 7 27.4.1. Radiation length . . . . . . . . . . . . . 17 27.4.2. Energy loss by electrons . . . . . . . . . . 18 2 7 . 4 . 3 .C r i t i c a le n e r g y .............. 2 2 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. ,PL B667 , 1 (2008) and 2009 partial update ±or the 2010 edition (http://pdg.lbl.gov) February 2, 2010 15:55
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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. The kinematic variables β and γ have their usual meanings. Symbol DeFnition Units or Value α ±ine structure constant 1 / 137 . 035 999 11(46) ( e 2 / 4 π± 0 ~ c ) M Incident particle mass MeV/ c 2 E Incident part. energy γMc 2 MeV T Kinetic energy MeV m e c 2 Electron mass × c 2 0 . 510 998 918(44) MeV r e Classical electron radius 2 . 817 940 325(28) fm e 2 / 4 0 m e c 2 N A Avogadro’s number 6 . 022 1415(10) × 10 23 mol 1 ze Charge of incident particle Z Atomic number of absorber A Atomic mass of absorber g mol 1 K/A 4 πN A r 2 e m e c 2 /A 0 . 307 075 MeV g 1 cm 2 for A = 1 g mol 1 I Mean excitation energy eV ( Nota bene! ) δ ( βγ ) Density e²ect correction to ionization energy loss ~ ω p Plasma energy p ρ ± Z/A ²× 28 . 816 eV ( p 4 e r 3 e m e c 2 )( ρ in g cm 2 ) N c Electron density (units of r e ) 3 w j Weight fraction of the j th element in a compound or mixture n j number of j th kind of atoms in a compound or mixture —4 αr 2 e N A (716.408 g cm 2 ) 1 for A =1gmo l 1 X 0 Radiation length g cm 2 E c Critical energy for electrons MeV E μc Critical energy for muons GeV E s Scale energy p 4 π/α m e c 2 21.2052 MeV R M Moli` ere radius g cm 2 February 2, 2010 15:55
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27. Passage of particles through matter 3 27.2. Electronic energy loss by heavy particles [1–32] 27.2.1. Moments and cross sections : The electronic interactions of fast charged particles with speed v = βc occur in single collisions with energy losses E [1], leading to ionization, atomic, or collective excitation. Most frequently the energy losses are small (for 90% of all collisions the energy losses are less than 100 eV). In thin absorbers few collisions will take place and the total energy loss will show a large variance [1];
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This note was uploaded on 12/30/2011 for the course PHYSICS 751 taught by Professor Eno during the Fall '11 term at Maryland.

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rpp2009-rev-passage-particles-matter - 27. Passage of...

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