Highly-Charged Ions in the ecr Discharge Sustained by Millimeter-Wave Radiation pra-0076

Full Title Creation of Highly-Charged Ions in the ECR Discharge Sustained by Millimeter-Wave Radiation Tech Area / Field

PHY-PFA: Physics / Particles, Fields and Accelerator Physics

MAT-SYN: Materials / Materials Synthesis and Processing

Brief Description of Technology The sources using microwave discharge plasma sustained in an open magnetic trap under the conditions of electron-cyclotron resonance (ECR) recently have begun to be considered as prospective sources of multi-charged ions (MCI). Such ECR sources are intended primarily for ion injection into cyclotron accelerators, the efficiency of which strongly depends on the efficiency of the ion source. Materials processing by MCI appears to be a very promising area, too.

The essential increase of electron-cyclotron resonance (ECR) multiply-charged ion (MCI) source efficiency (that is, the increase of the average charge number and current of ion beams) leads to the possibility of achieving denser plasma, and its transfer to the so-called quasi-gas dynamic regime of the plasma confinement in mirror traps as a result of pumping with higher frequency. The first experimental investigation of ion charged state distribution in a pulsed ECR source of MCI with pumping by millimeter wave radiation of a powerful gyrotron were carried out in IAP RAS.

Millimeter wave radiation with a maximum power of W=130 kW, frequency of f=37.5 GHz and pulse duration of up to 1.5 ms was focused along magnetic lines into the trap with a mirror ratio of 3,3. Gas pressure was tuned by a pulsed inlet and maintained on level at more than 310^-5 Torr. The plasma density measured by cutting off diagnostic millimeter waves exceeded 2  10¹³ cm^-3. The ions that flew freely along the axis of the trap were investigated by a two-step ion analyzer (magnetic and electrostatic analysis) with a mass resolution of 3, and by a Langmuir plate probe. If W=130 kW, the position of the charged state distribution maximum corresponded to an argon charge of (+11)-(+12), whereas in the modern ion sources (with pumping by microwave power of centimeter wavelength) the distribution maximum corresponded to a charge of (+8). Total ion saturation current density of the probe achieved 2 A/cm². Thus, high plasma density (more than the order of magnitude exceeding density in traditional sources) and high ion current in our system provide the hope of achieving MCI beams with previously unattainable currents.

Legal Aspects None.

Special Facilities in Use and Their Specifications None.

Scientific Papers S.V. Golubev, S.V. Razin, V.G. Zorin. “Investigation of ion charge state distribution in the ECR source with pumping by gyrotron radiation,” Abst.of 3-rd Int. Workshop "Strong Microwaves in Plasmas," (Nizhgny Novgorod, Aug. 1996), D-14.

Atmospheric Spectroscopy Distance in the ir Range up to 10 Kilometers pra-0077

Full Title Extension of the Atmospheric Spectroscopy Distance in the IR Range up to 10 Kilometers Using Powerful Parametric Converters and Amplifiers Tech Area / Field

PHY-OPL: Physics / Optics and Lasers

OBS-NAT: Other Basic Sciences / Natural Resources and Earth Sciences

Brief Description of Technology We have performed investigations of optical parametric oscillators (OPO) and optical parametric amplifiers (OPA), which show the possibility of creating on the base of LiNbO₃ and LiIO₃ crystals effective parametric converters of radiation from Nd-lasers with pulse energy up to 1-2 J. It has been shown that the operation of such converters in both the "single-frequency" and "dual-frequency" regimes — with the line width not more than 0.2 cm^-1, and the spacing between the lines (in the "dual-frequency" regime) at 1.5-3.0 cm^-1 — is quite possible.

Legal Aspects None.

Special Facilities in Use and Their Specifications None.

Scientific Papers F.I. Feldshtein, G.I. Freidman, V.V. Lozhkarev, G.A. Pasmanik, A.A. Shilov, I.V. Yakovlev. "Prospects of Using Parametric and SRS Oscillators and Amplifiers for Remote Spectroscopy of the Atmosphere and Image Amplification," Proc. SPIE, vol. 2797, 1996.

G.I. Freidman, G.A. Pasmanik, A.A. Shilov, D.G. Peterson. "Some New Possibilities to Design Frequency-Tunable Lidars in the IR (2:14 mm)," Proc. SPIE, vol. 2366, pp. 403-407, 1995.

A.A. Babin, N.N. Belyaeva, Yu.N. Belyaev, V.I. Bradikhin, F.I. Feldshtein, G.I. Freidman, A.V. Karov, V.N. Petryakov. "Powerful Tunable IR Sources Based on OPO, Parametrical and SRS Converters [in Russian]," Izv AN SSSR, Ser. Fiz., Vol. 48, No. 8, pp. 1511-1521, 1984.

G. Freidman, V. Lozhkarev, J. Partin, G. Pasmanik, D. Peterson, E. Shklovsky, I. Yakovlev. "Enhanced OPO/OPA IR Source," CLEO '97, Technical Digest, p. 456, 1997.

G. Freidman, V. Lozhkarev, A. Matveyev, J. Partin, G. Pasmanik, D. Peterson, E. Shklovsky, I. Yakovlev. "Raman Converter of Tunable Radiation into Mid/Far IR with Large Shift of Stokes Wavelength," CLEO'97.

Active Sounding of the Atmosphere by Powerful Microwave Radiation PRA-0078

Full Title Active Sounding of the Atmosphere by Powerful Microwave Radiation Tech Area / Field

OBS-NAT: Other Basic Sciences / Natural Resources and Earth Sciences

Brief Description of Technology At present the importance of the microwave monitoring of clouds and aerosols is evident. This is a unique tool for investigating a wide class of water and ice clouds, as well as some air pollutions, which are practically "invisible" for centimeter wavelength meteoradars and, at the same time, opaque for optical radiation. In recent years a number of proposals have been formulated to use modern, high-power electron cyclotron masers (gyrotrons) for microwave monitoring with high sensitivity. Our experiments are based on the use of unique microwave generators (gyrotrons) created in IAP RAS, and the highly sensitive receivers also constructed in IAP. To interpret the experimental results, detailed numerical simulation will be performed of the scattering processes in different types of clouds and in the clear atmosphere. These experiments will allow us to investigate a number of effects in the atmosphere, such as: Rayleigh and non-Rayleigh scattering mechanisms, multiple scattering and the depolarization of radiation. Provided the device is created with this experimental technique, it will demonstrate good performance as a bistatic meteoradar and will be further developed to constitute a basis for a powerful mobile sounding system.

Legal Aspects None.

Special Facilities in Use and Their Specifications None.

Scientific Papers Manheimer W.M., Mesyats G.A., Petelin M.I. “Applications of High Power Microwave Sources to Enhanced Radar Systems,” Applications of High Power Microwaves, Eds. A.V.Gaponov-Grekhov, V.L. Granatstein, Artech House, Boston, London, p. 364, 1994.

Bykov Yu.V., Dryagin Yu.A., Eremeev A.G., Kukin L.M., Lebsky Yu.V., Mocheneva O.S., Tokman M.D. “High-Power Microwave Radiation Scattering in the Clear Atmosphere,” Izv. AN, Fizika Atmosfery i Okeana, v. 32, No. 1. pp. 84-87, 1996.