In 1978-79, J. J. Murray, Robert Avakian, Ivan Miroshnichenko, and Ted Fieguth
conducted a channeling radiation experiment using positrons in beam line 19 and using the same goniometer that is now going back into A-line for E159, E160 & E161. The diamonds (2) that we used are still mounted in place as they were 23 years ago. Here is what Ted found for the measurements.One sends one positron/pulse and get one photon per pulse
Positron Energy___Gamma Theory___Gamma Measured
__GeV__________MeV__________MeV
___2_____________11___________9.3
___4_____________30___________26
___6_____________53___________45
__10_____________90___________84
_14____________125__________120
__16____________150__________138
To utilize this for GLAST we would set Aline polarity for positive
particle just as we did for the Proton run and than either use the proton target, for which the yield will be excessive or use a Sector 29 profile monitor to generate secondary positrons. One thing that would need attention is how to avoid pile up. He recalls that he had some difficulty with that and needed special de-convoluting software to remove it.