sentences:  In terms of power-for-cost, HiPER is expected to be about an order of magnitude less expensive than conventional devices like NIF.Compression is already a fairly well-understood problem, and HiPER is primarily interested in exploring the precise physics of the rapid heating process.It is not clear how quickly the electrons stop in the fuel load; while this is known for matter under normal pressures, it's not for the ultra-dense conditions of the compressed fuel.