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Subroutines

GBREME generates a bremsstrahlung photon from an electron as a discrete process. The photon energy is sampled from a parameterisation of the bremsstrahlung cross-section of Seltzer and Berger [] for electron energies below 10 GeV, and from the screened Bethe-Heitler cross-section above 10 GeV. Midgal corrections are applied in both cases. The angular distribution of the photon is calculated by the function GBTETH.

Input : via common block /GCTRAK/
Output: via common block /GCKING/.

GBREME is called from the tracking routine GTELEC when the parent electron reaches a radiation point during tracking.

GBTETHTHETA = GBTETH(ENER,PARTM,EFRAC)

THETA: ( REAL) angle of the radiated photon or $e$ ^±
pair;
ENER: ( REAL) energy of the particle;
PARTM: ( REAL) mass of the particle;
EFRAC: ( REAL) ratio between the energy of the photon and the energy of the particle.

GBTETH calculates the angular distribution of the

e

⁺e^- -pair in photon pair production and of the emitted photon in

μ

and

e

^± bremsstrahlung. GBTETH is called by GBREME.

Janne Saarela
Mon Apr 3 12:46:29 METDST 1995

Input :	via common block /GCTRAK/
Output:	via common block /GCKING/.