Use of gamma rays from the decay of 13.8-sec {sup 11}Be to calibrate a germanium gamma ray detector for measurements up to 8 MeV

Gamma rays from the {beta}{sup {minus}} decay of 13.8-sec {sup 11}Be can be used for Ge photon detector efficiency calibration at energies > 2--3 MeV that are not accessible using more conventional gamma-ray sources. {sup 11}Be is generated by the {sup 11}B(n,p){sup 11}Be reaction using a boron oxide sample and 14-MeV neutrons from a neutron generator. The short-lived activity is carried to the detector using a pneumatic transport system. This paper describes the experimental method used and provides an example of a Ge detector efficiency calibration curve augmented by this technique