The basements of large buildings made from concrete spring to mind, then geographical areas that are at or below sea level.
Random thought: anti-coincidence detector? A detector above the RAM chips and one below with data processing set so that if the detector above gets a count and the one below does not or sees a count with significantly lower energy, you know some energy has been absorbed somewhere near the RAM.
Random thought: anti-coincidence detector? A detector above the RAM chips and one below with data processing set so that if the detector above gets a count and the one below does not or sees a count with significantly lower energy, you know some energy has been absorbed somewhere near the RAM.