Neutrino detector design, attenuation studies, and testing for the νSol project

Abstract

In order to further work on the Sol project funded through a NASA Phase II NIAC grant, I have performed detailed simulations on the effect of attenuation length on the performance of the Sol solar neutrino probe using varying energies of electrons and gamma rays. I have worked to prepare a container to hold our liquid scintillator in order to perform initial measurements on the ground in order to verify simulation, and have simulated cosmic ray showers for this comparison. I have also simulated the results of a triggered gamma ray source incident on the scintillating volume, but there is not test stand data at this time. The electron simulations are promising, and suggest that for a .044m vessel, a 0.383 m attenuation length is a sufficient minimum for reading rich signals. The gamma ray simulations suggest that for the same vessel a 2m attenuation length is a sufficient minimum. In both cases, decreasing the length of the vessel provides a disproportionately large shrinking of the minimum attenuation length. Filtering for true and false 0-hit signals in the gamma sector should bring the minimum attenuation more in line with the electron’s minimum and allow us to include more dopant in our detector. I have learned that simple heat sealing is not a feasible solution for a plastic liquid scintillator container. A much higher pressure industrial environment may solve the problem, but the project would likely be better suited to injection or blow mold a vessel in that extreme. I have investigated a glassware solution, but have not yet received pricing information from the glassmaking company. For the meantime, we have settled on a high quality plastic glue, though we are not sure this is a feasible long-term solution for the final space-worthy device. The initial cosmic ray data matches the simulation data very closely. This result encourages the continuing project to move onto triggered gamma ray data when possible to verify the results of that experiment against the simulation.