1. A mobile in vivo infrared brain scan system, comprising: a helmet with a plurality of infrared (IR) probes, each of the IR probes having an quantum well IR photodetector capable of detecting IR radiation generated by evoked potentials within a user's skull, whereby while wearing the helmet, a user can collect in vivo brain data; a plurality of mounting cap assemblies attached with the helmet, such that each of the IR probes is affixed with the helmet using a corresponding mounting cap assembly, each mounting cap assembly housing a pressure-apparatus that is in contact with an IR probe and that is formed to force the IR probe away from the mounting cap assembly and toward a user's scalp; and further comprising: a cold finger attached with the quantum well IR photodetector and a cold source passing through the mounting cap assembly and attached with the cold finger to cool the cold finger and thereby cool the quantum well IR photodetector; and a cold filter attached with the IR probe such that a space of evacuated volume exists between the quantum well IR photodetector and the cold filter.