The Design and Expected Performance of the BL3 Proton Detector

The BL3 collaboration is currently developing the next-generation neutron beam lifetime apparatus with the goal of improved systematic precision in the neutron lifetime to the sub-second level. This experimental technique requires both an absolute measurement of neutron flux through a quasi-Penning trap and an absolute measurement of the number of beta decay protons trapped within this volume. In this talk, we present the design and expected performance of a novel proton detector system tasked with measuring the absolute count rate of protons delivered from the BL3 trap. This system uses a temperature-controlled segmented silicon detector which is held at a high-voltage accelerating potential and suspended into the cryogenic volume of the experiment. The mechanical, thermal, and electrostatic design of this system will be outlined. The expected performance of the detector and associated electronics will be characterized with simulation results and preliminary measurements. Finally, the status of the assembly and testing of this system will be presented.