Extending the range of the time projection Compton spectrometer to lower energy

The authors investigated the application of the time projection Compton spectrometer (TPCS) to photoelectron spectrometry, using a 2-μm-thick gold target to improve device sensitivity to low-energy photons. Experiments with a gold target, a polypropylene target, and no target (background) were performed for various endpoint bremsstrahlung up to about 2 MV. Response functions are calculated using the TIGERP electron/photon Monte Carlo code. The signal from gold is larger and persists longer, as expected. The spectrum unfold from the gold signals has problems. Alternate approaches to the unfold problem that combine data from both targets may prove more successful