A method for the detection of atomic hydrogen.

A recombination bolometer for the detection of atomic hydrogen was designed and constructed. The bolometer consisted of a platinum disk, to the back of which was bonded a small bead type thermistor. The recombination of atoms upon the surface of the disk provided sufficient heat that a substantial change in the resistance of the thermistor was observed. As part of a testing program for the device, the relative sensitivity defined as (change in temperature/relative number of atoms present) was measured for atomic hydrogen, nitrogen and oxygen. Since the three atoms studied are paramagnetic, it was possible to determine their relative populations by making use of a μ-wave absorption spectrometer. The results of the sensitivity measurements yielded a nitrogen sensitivity of .083 and an oxygen sensitivity of .0024, where the hydrogen sensitivity is taken to be unity. The "decay time", defined as the time required for the temperature of the device to drop 63.2% of the total temperature change when the radicals were turned off was measured to be 15 seconds vs. a calculated value of 25.5 seconds