Anomalous plasma phenomena of hollow cathode arc discharge

Magnetically confined argon plasma produced by hollow cathode arc discharge has been studied in different experimental conditions, with discharge current from 10–50 A, vessel argon pressure between 10^–3 and 10^–4 torr (1 torr=133·32 Pa) and axial magnetic field up to 0·12 T. The plasma density measured by a cylindrical Langmuir probe is found to be 10¹⁹ to 4 × 10¹⁹ m^–3 and the electron temperatureT _e varies between 2·5 and 4·8 eV. When an external axial magnetic field is applied the plasma temperature decreases with the increase in the magnetic field intensity until it reaches a minimum value at 0·075T and then increases with the same rate. This has been interpreted as high frequency waves excitation due to electron beam-plasma interaction, which explains the electron density jumps with the magnetic field intensity. Enhanced plasma transport across the magnetic field is studied and classified as anomalous diffusion.     

Glow discharge with an annular hollow cathode

A discharge system with peripheral discharge chambers (Penning cells) and common hollow cathode with only one cell supplied with power is studied. It is shown that a jumpwise transition from a dark discharge to a glow discharge is accompanied by the penetration of plasma into the hollow cathode.     

Laser action in a gallium hollow cathode discharge

cw laser action was observed for the 6335 and 7199 Å transitions of Ga II in a hollow cathode discharge. Charge exchange and radiative cascade processes are suggested to be responsible for the population of the upper laser levels.     

Beam-plasma mechanism for anode plasma generation in a low-pressure two-stage self-sustained discharge with a cold hollow cathode

Results are presented from experimental studies of the anode region of a low-pressure two-stage self-sustained discharge with a closed cold hollow cathode. It is shown that applying an external longitudinal magnetic field promotes the generation of a dense anode plasma, whereas the transverse field impedes this generation. It is established that the beam-plasma mechanism for plasma generation plays a dominant role in the anode region of the discharge. The geometry of the electrodes of the gas-discharge chamber is optimized.     

Electron transport properties of stationary plasma clouds generatedwith hollow cathode discharges

The electron transport properties of plasma clouds generated by a hollow cathode discharge are investigated. The voltage-current characteristic curves indicate that the electron-emitted electron current depends on both bias voltage and discharge current. The spatial dependence of the electronic density, plasma potential, and electronic temperature is measured. The energy loss rate of a high energy group of electrons with the radial distance is also presented. These experimental results are compared with a nonisothermal transport model which reproduces the spatial dependence of plasma properties     

CW laser oscillation in a hollow cathode He-Kr discharge

CW laser oscillation on the 4694 Å transition of Kr II has been observed in a hollow cathode He-Kr discharge.     

Intermodulated optogalvanic Zeeman spectroscopy in a hollow cathode discharge

The Zeeman and hyperfine structures of various transitions of calcium, copper, and neon are investigated by means of Doppler-free optogalvanic spectroscopy. This work demonstrates the suitability of the hollow cathode discharge to high resolution Zeeman spectroscopy of refractory and reactive elements.     

Atomic nitrogen laser action in a hollow cathode discharge

Near-infrared laser action of nitrogen atoms was obtained in a hollow cathode discharge. Four laser lines at wavelengths of 1358.2, 939.3, 938.7, and 862.9 nm were observed in the cw mode. In addition, the laser line at 904.6 nm was observed in quasi-cw operation in the afterglow for the first time. It is supposed that resonant charge exchange between He⁺ and N₂ followed by predissociation of N ₂ ⁺ is an important way of populating the upper laser levels.     

HeKr laser with transverse hollow cathode discharge

Quasi-CW laser generation on five KrII lines in HeKr gas mixtures is observed using sectioned hollow cathode construction in which transverse discharge is realized. Gain of 19%/m and output power of 34 mW are achieved. Single longitudinal mode operation is obtained.     

High-power discharge with a plasma cathode in dense gases

An attempt is made to create an electric-discharge source for pumping argon, krypton, and xenon dimer lasers. The device is based on a method proposed previously by the authors, wherein confinement of the discharge is achieved by removing the cathode spot from the main discharge region and closing the discharge to the spot along a narrow extended auxiliary plasma channel. The conditions for the formation of such a discharge are investigated. The high stability of the sparkless stage of the discharge permits the first-ever attainment of energy depositions at the level of 100 J/cm² at pressures ∼10 atm, a level several orders of magnitude higher than is attainable by conventional methods. A discharge cell and power supply system are designed for a multisectional discharge with an active length of 200 mm, and the reliability of the entire apparatus is demonstrated in long-term use. Zh. Tekh. Fiz. 67, 10–14 (November 1997)     

Study of the rectangular hollow cathode discharge

The rectangular hollow cathode discharge is studied with respect to the applicability of similarity mechanisms analogously to other gas discharge types. Probe characteristics of the discharge are measured, the conditions of steady and continuous discharge glow in the cathode cavity are determined.