Microwave excitation of a low-energy atomic hydrogen

Abstract

Performances of microwave driven compact neutral beam sources of different plasma excitation configurations have been compared in producing directed low energy atomic beams for biomolecular structural analyses. The beam sources include unique impedance matching systems in themselves for reducing the size of the source; a multi-turn spiral antenna successfully excited a hydrogen plasma in a 4 mm inner diameter Al 2 O 3 tube by 2.45 GHz microwave power. A combination of a mirror magnetic field and electron cyclotron resonance has been found effective to realize a source operation at a low operating pressure (∼10 −3 Pa). This magnetic field configuration produced a hydrogen plasma with the optical emission spectrum predominated by atomic lines indicating a high degree of dissociation. The plasma excited in this type of source exhibited a mode transition like behavior which was not confirmed in other source geometries.

Verified modeling of a low pressure hydrogen plasma generated by electron cyclotron resonance

“…Low pressure hydrogen plasmas are of great interest to a plethora of industrial sectors including multiple stages of semiconductor fabrication [1][2][3][4], diamond-like carbon film manufacturing [5,6], and for their usage as a hydrogen radical source [7]. Equally, the interaction between a hydrogen plasma and a surface is of prominent importance in a number of academic research fields such as negative ion generation for neutral beam injection [8][9][10] and ammonia synthesis [11][12][13].…”

Improvement of Velocity Distribution Function Measurement of Hydrogen Atoms in ion Source Discharges

“…Meanwhile, Ivanov et al installed arc discharge atomic hydrogen sources to their Hion source to increase Hsurface production by H 0 impact [4]. Shimabukuro et al observed that the second mode jump can increase the power absorption by an electron cyclotron resonance (ECR) driven small plasma source to produce larger flux of fast H 0 atoms [5]. To clarify if these atom sources can create H 0 atoms fast enough to produce Hion efficiently by surface production process, a project to construct a system to measure the H 0 velocity distribution function was initiated [6].…”