# 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:










## 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 a 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

Here I just plotted the table above for pair production cross section in (0, 40) MeV energy region