AN ARC-DISCHARGE HYDROGEN-ATOM SOURCE

A magnetically confined thermal electric arc gas heater of easy constr uction, handling, and maintenance has been designed, built, and tested as a suitable source of heat for dissociating hydrogen molecules. The plasma species in the gas discharge region are assumed to satisfy loc al thermodynamic equilibrium conditions. The average beam kinetic ener gy is determined to be 1.5 eV, leading to an arc temperature of approx imately 8700 K; the dissociation rate is 0.5 atoms per molecule and th e total atom beam intensity in the forward direction is 10(18) atoms/s r s. This novel atom source has been successfully ignited and operated with pure hydrogen during several hours of continuous performance, ma intaining its characteristics and overcoming some of the difficulties previously found by researchers using other arc sources. The hyperther mal hydrogen atom beam obtained from this source is identified by MoO3 chemical detectors, and analyzed and characterized by three different calorimetric sensors, Ni, Ta, and Teflon. The experimental results ob tained with this dissociator agree with those published in the literat ure.