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.