The cartoon below gives a crude idea of the experimental setup.  Neutrinos occasionally interact with the ice and give off radiation (a rare event).  The radiation (green lines) is detected by antennas (red dots).  The antenna signals are fed to a data acquisition system in a building on the surface where they are digitized.

The problem is that similar radiation is generated from the surface (blue lines) at vastly higher rates.  Every time one of these events occurs, it ties up the data acquisition for "a long time" (milliseconds) so that possible neutrino events would be lost.

The HSV board can detect and screen out many of these spurious events before they reach the data acquisition system (about a microsecond), making the system vastly more efficient.   Continue . . .