THERMAL DETECTION OF ESR-INDUCED SURFACE RECOMBINATION OF SPIN-POLARIZED HYDROGEN

A new ESR detection method is described for atomic hydrogen where, ins tead of observing the microwave power absorbed in the ESR transition, we monitor the recombination heat deposited by spin-flipped atoms onto a carbon-film bolometer. The density detection limit of 2.10(10) cm-3 has been achieved at 150 mK for an 0.2% s-1 atom loss rate. We have e xtracted the second-order surface recombination rate constant from the cooling rate of the bolometer after ESR excitation pulses at temperat ures between 200 mK and 400 mK.