Journal of Research of the National Institute of Standards and Technology vol:110 issue:4 pages:415-420
Results of the first experiment to search for the radiative decay mode of the free neutron are reported. The gamma-spectrum was studied in the energy region from 35 keV to 100 keV in six Cs(T1) scintillators, each set at an angle of 35 to, and shielded from, a central plastic scintillator electron detector. Triple coincidences were recorded with recoil protons detected in a micro-channel plate. A limit for the branching ratio BR <6.9x10(-3) (90% confidence level) was obtained, which is greater that the theoretical prediction by not more than a few tenths of a percent.