Abstract: In the ICF experiments, we have applied newly developed small GaAs-photoconductor detectors made with neutron -treated GaAs crystal material. Hard X -ray signals and hard X-ray angular distribution have been obtained with the detectors. The sensitivety to the X rays is about 10^-18C/keV and the response about 100ps. The detectors have the ability against electromagnitic radiation inferfere in the target chamber.