J. D. Meyer

Glow‐discharge‐created electron beams: Cathode materials, electron gun designs, and technological applications

The operating characteristics of glow‐discharge‐created electron beams are discussed. Ten different cathode materials are compared with regard to maximum electron beam current achieved and the beam generation efficiency as measured calorimetrically. Specific electron gun designs are presented for a variety of applications that include: cw ion laser excitation; electron beam assisted chemical vapor deposition of microelectronic films; and wide area annealing of ion‐implantation damage to silicon substrates. The use of sintered metal‐ceramic (e.g., Mo‐Al2O3) cathodes to generate multikilowatt electron beams in a pure noble gas discharge is reported. Cathode materials with high secondary electron emission coefficients by ion bombardment allow for electron beam production in glow discharges at 50%–80% generation efficiency values.

Transverse electron guns for plasma excitation

We report a plasma gun, which generates on a continuous basis, kilowatt electron beam discharges (e.g., 0.4 A at 4 kV) in an ambient pressure 0.1–1 Torr without differential pumping. Gun design characteristics, operating parameters, and measured beam profiles are given. Electron beam generation on a pulsed basis has also been studied. More than 100 A of beam current has been measured with a Faraday cup biased to −100V. A trapped electron beam scheme for achieving efficient deposition of the electron beam energy in a gas medium is described.

1‐W cw Zn ion laser

We have obtained 1.2 W of cw laser power on the 4911.6‐ and 4924.0‐A transitions of Zn II by exciting a He‐Zn gas mixture with a dc glow discharge electron beam. In addition, 0.25‐W output power has been obtained on the 6149.9‐A line of Hg+ using the same excitation scheme. The combination of electron beam ionization of rare gas atoms and subsequent charge transfer excitation to metal ion levels is shown to have the potential of significantly increasing the efficiency of ion lasers. cw multiwatt visible and ultraviolet ion lasers operating at efficiencies >10−3 appear feasible using this excitation scheme.

Hollow cathode electron gun for the excitation of cw lasers

Abstract Well collimated electron beam discharges with an energy of 1 kW, at currents up to 0.1 A, have been obtained at ambient pressures up to 0.4 Torr in Ar and 1.4 Torr in He using hollow cathode electron guns. The guns operate on a continuous or dc basis. These guns have the unique feature of providing a clear optical path through the axis. We suggest the use of such an electron beam discharge for excitation of cw ion lasers.

Cw laser oscillations in Cd II in an electron beam created plasma

Abstract A cw Cd II laser has been demonstrated using electron beam excitation. Cw laser oscillation has been obtained on six transitions of Cd II in a HeCd plasma. Output power as a function of electron beam discharge parameters has been investigated.

Electron beam pumped cw Hg ion laser

We have obtained cw laser action using electron beam excitation of a He‐Hg mixture. This represents a new method of exciting cw lasers and offers the possibility of increased efficiency for ion lasers.

CW iodine ion laser excited by an electron beam

CW laser oscillation has been obtained on the 5760.7 and 6127.5 A transitions of singly ionized iodine in an He-I 2 plasma excited by a dc electron beam.

Influence of electron collisions inside the cathode sheath upon the electron energy spectrum in the negative glow region of a gas discharge

Computer models developed to solve the Boltzmann equation for the electron energy spectrum in both the cathode sheath and the negative glow region of a glow discharge are discussed. Electron collisions occurring during acceleration inside the cathode sheath partially determine the structure of the electron energy distribution measured in the negative glow. The relative roles of elastic, excitation, and ionization collisions are examined using the computer model. Good qualitative agreement was obtained between calculated electron energy distributions and previous experimental measurements both at the sheath-plasma interface as well as in the negative glow region of the discharge. >

CW laser action in atomic fluorine

We have obtained CW laser action on four transitions in the doublet system of atomic fluorine for the first time. All previously reported laser action was on a pulsed basis only. CW laser radiation was obtained when F 2 or AgF was used as a fluorine donor in an electron beam pumped helium plasma. A multiline output power of 200 mW was obtained.

Electron beam pumped CW Se II laser

Abstract We have observed cw laser action in 15 transitions of singly ionized selenium using an electron beam to excite a He-Se mixture. The variation of the laser output power as a function of the electron beam discharge parameters is reported.