摘要:

A discussion was held to address constraints affecting the advancement of laser technology and applications. Several issues were raised such as the regulatory issues of safety and standards. The thermal constraints on laser materials affecting the laser’s overall efficiency etc. were also considered. The issue of scientific secrecy relative to recent advances in laser technology was also brought up. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.36854

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

High‐power chemical lasers thrive in an array of special environments and present many fascinating associated subjects ripe for developmental research. Included are processes to produce the source reactants; supersonic mixing and reacting flow fields; the production and dissipation of multiple vibrational‐rotational molecular states; optical gain extraction in complex geometries; media inhomogeneity effects, and waste energy and reaction products removal. Some configurations require wavelength selectivity, special optical components, and coherent cavity or beam combining. In recent years, progress has been made in these areas on behalf of continuous‐wave and repetitively pulsed hydrogen fluoride and deuterium fluoride lasers, subsonic and supersonic oxygen‐iodine lasers, and potential shorter wavelength chemical lasers based on chemically excited higher electronic states. This paper presents a brief review of the technical approach of some of the technology areas, and the status in achieving practical, integrated high‐power chemical lasers.

ISSN:0094-243X    

DOI:10.1063/1.36732

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This paper traces the author’s involvement in the early development of high power lasers. Over a brief period in the early 1960’s the concepts of the gasdynamic laser, the mixing laser, and laser‐induced implosions were spawned at Cornell Aeronautical Laboratories.

ISSN:0094-243X    

DOI:10.1063/1.36866

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This paper reports on a semi‐empirical model of an injection‐controlledXeF(C → A) excimer laser. Calculated results are compared with experimental data on injection timing, injection gain, and cavity magnification for an unstable resonator geometry.

ISSN:0094-243X    

DOI:10.1063/1.36858

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Peformance of a pulsed DF‐CO2transfer laser was investigated both for photolytic initiation and for transverse initiation by a magnetically‐confined electron beam. Laser output is presented as a function of e‐beam charge fluence, O2concentration, F2and D2concentration, diluent gas, initiation level and total mixture pressure. The experimental results are in agreement with a comprehensive DF‐CO2laser model. The DF‐CO2laser performance is found to be comparable to that of a DF chain laser using mixtures of comparable chemical energy content.

ISSN:0094-243X    

DOI:10.1063/1.36789

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Investigations of a high‐power, transverse‐flow, transverse‐discharge, closed‐cycle cw CO2laser are reported. The laser has been designed as a laboratory facility, primarily for the materials processing research.

ISSN:0094-243X    

DOI:10.1063/1.36779

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Laser‐driven inertial confinement fusion (ICF) experiments are being performed at several laboratories throughout the world. Nearly all are seeking to demonstrate compressed fuel densities of several tens g/cm3. For ICF to be an efficient process, it is desirable to compress the fuel along a near‐Fermi degenerate adiabat to densities of several hundred g/cm3. Addition of thermal energy prior to achieving the compressed state is detrimental in that a significantly larger driver would be required to achieve ignition. Preheating of the fuel prior to compression may result from radiation or thermal electron conduction, or non‐isentropic processes such as shock heating. Recent experiments at KMSF sought to control these by a combination of target and laser parameters. Using a spherical illumination system, the target is irradiated with a carefully prescribed temporal pulse of frequency doubled neodymium glass laser light. Low preheat targets are designed with thick polymer (poly vinyl alcohol) shells and cryogenic fuel layers. The implosion process is recorded by a number of optical and x‐ray diagnostics. A four‐frame holographic interferometer records the temporal evolution of the ablated plasma while an x‐ray pinhole camera records the symmetry of the compressed core. The most important diagnostic is the combined x‐ray backlighter/streak camera combination which records the implosion trajectory in one dimension. A comparison of the data from these three major instruments with the results from the hydrodynamic simulation code allows one to interpret the final state the fuel reached and thus, the preheat level. Assuming spherical symmetry, record fuel densities in excess of 35 g/cm3have been achieved.

ISSN:0094-243X    

DOI:10.1063/1.36759

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Because of a renaissance in concepts, the past few years have seen a substantial increase in the level of research aimed at the determination of the feasibility of a gamma ray laser. The essential concerns are reviewed in this presentation.

ISSN:0094-243X    

DOI:10.1063/1.36740

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The advantages of utilizing the 2‐beam Borrmann modes of a crystalline, rather than an amorphous, sample for the lasing modes of a &ggr;‐ray laser (reduced lasing threshold and higher gains above threshold, due to reduced photoabsorption and improved coupling between the lasing mode and the nuclei) are well known. We discuss here the further improvements which are obtained in multi‐beam (3 or more) Borrmann modes. These modes would be fed automatically by emitters of multipole M1 or higher located within the crystal. As an example, the 6‐beam mode which couples well to M1 emitters would have a lower threshold than a similar 2‐beam mode. More importantly, the slope of the net gain vs. population inversion density curve would be three times greater in the 6‐beam mode, allowing practical levels of gain to be reached at much lower inversion densities.

ISSN:0094-243X    

DOI:10.1063/1.36817

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This paper describes the progress in construction and scaling of a flash x‐ray device producing intense nanosecond pulses to excite nuclear fluorescence for the evaluation of candidate materials for a gamma ray laser.

ISSN:0094-243X    

DOI:10.1063/1.36837

出版商:AIP    

年代:1987

数据来源: AIP