# Difference between revisions of "Number of electron-positron pairs/sec out of Al converte"

## LINAC parameters used in calculations

1) pulse width 50 ps
2) pulse current 50 A
3) repetition rate 300 Hz
4) energy 44 MeV

## Number of photons/sec out of radiator






Alex factor is 6.85 %




## Pair production rate

### out of Al converter



 (by varying width we can vary the yield)






### through 1 m of air

Assume air consists entirely from Nitrogen:

 (better to plot and to check this number but it's maybe factor of 2)








## Appendix

### pair production cross sections in an Al target

Ref. Geant4 and Theoretical Pair Production Cross Sections for 1 MeV - 100 GeV photons in Aluminum. Vakho Makarashvili, December 18, 2007

### pair production cross sections in Nitrogen

Ref. Photon Cross Section, Attenuation Coefficients, and Energy Absorption Coefficients From 10 keV to 100 Gev. J.H.Hubbell. Center for Radiation Research.National Bureau of Standards. Washington, D.C. 20234