摘要:

The photoionization of a large organic molecule, tri‐n‐propyl amine, mixed with a 1‐atm CO2&sngbnd;N2&sngbnd;He gas is used to produce a high‐electron‐density uniform large‐volume laser plasma. Photoionization by a two‐photon two‐step process is found to be the dominant mechanism when illumination is by a xenon flashlamp employing a quartz envelope. Electron density on the order of 1013/cm3is obtained. The electrons are heated by an externally applied electric field less intense than that required to produce avalanche breakdown. Laser oscillation is observed on theP(20) line of the 10.6‐&mgr; CO2band with a maximum output of 300 mJ obtained from a 0.02‐liter active volume (corresponding to 15 J/liter). The energy output as a function ofE/Pis studied and found to peak at a value below breakdown.

ISSN:0003-6951    

DOI:10.1063/1.1654555

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The first absorption band for an irradiation‐induced defect in SiGe alloys has been observed at 2.15‐&mgr;m (90 K) in Si0.5Ge0.5following neutron or proton bombardment. The 2.15‐&mgr;m band is similar in width and thermal stability to the 1.7‐&mgr;m divacancy band in Si, but the band position is closer to a 2.4‐&mgr;m band tentatively ascribed to divacancies in Ge. A distinct divacancylike band in the bombarded SiGe suggests either some structural order in the alloy or structural selectivity in defect formation. Absence of characteristic Si or Ge bands implies that the alloy is free from any significant amount of Si or Ge aggregates.

ISSN:0003-6951    

DOI:10.1063/1.1654556

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A simple exoelectron emission microscope is described, first images obtained from BeOceramic are reported, and potential applications of the device in surface characterization of a wide variety of solids are discussed.

ISSN:0003-6951    

DOI:10.1063/1.1654557

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Si epitaxial growth from solution in solid Al onto crystal Si substrates was studied by scanning electron microscopy. Growth in reentrant corners of the substrate was found to be favored over growth onto a flat surface. For this reason, the smaller‐diameter oxide cuts used in integrated‐circuit fabrication, in which no portion of the exposed substrate Si is far from a reentrant corner, are favored sites for growth. Si growth readily fills in such oxide cuts forming mesa structures potentially useful in device construction. The probable cause for such preferential growth was indicated in pressure experiments which show that regions in the solid Al under relatively less compression are favored locations for growth.

ISSN:0003-6951    

DOI:10.1063/1.1654558

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Intense aluminum fluoride laser pulses in the spectral range 12.5–13.5 &mgr; were observed when fine aluminum wires were exploded into fluorine gas. The laser oscillation occurred during the expansion phase of the wire explosion.

ISSN:0003-6951    

DOI:10.1063/1.1654559

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Ribbons of composition Nb3Al0.75Ge0.25have been fabricated by swaging, rolling, and heat treatment. Measurements ofJcin steady transverse magnetic fields up to 150 kOe at temperatures up to 16°K show values of the order of 104A/cm2at 13°K and 120 kOe, and 103A/cm2at 16°K and 95 kOe.

ISSN:0003-6951    

DOI:10.1063/1.1654560

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Fabrication details and experimental results are presented for metal‐Al2O3‐SiO2‐silicon capacitors intended as memory devices, for which the insulator layers are formed by plasma anodization. It is found that well‐controlled devices with stable characteristics may be realized by this method.

ISSN:0003-6951    

DOI:10.1063/1.1654561

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A LiIO3crystal, placed inside a doubly resonant oscillator, was pumped with the second harmonic of aQ‐switched ruby laser. A 0.415‐ to 2.1‐&mgr;m tuning range for both signal and idler was obtained. The conversion efficiency from pump to signal power amounts to 8&percent;. The peak power of the signal radiation was 10 kW and the pulse duration was 5 nsec.

ISSN:0003-6951    

DOI:10.1063/1.1654562

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

An oscillator‐amplifier iodine laser system has been set up to demonstrate the feasibility of high‐power operation of this laser. Pulse powers of 1.2 GW have been obtained with two amplifier stages. Technical details and relevant laser parameters are discussed.

ISSN:0003-6951    

DOI:10.1063/1.1654563

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Previous N2and H2electronic transition lasers have been limited to short pulse durations (10−9–10−7sec). Using an electron‐beam‐stabilized discharge in argon, nitrogen (or hydrogen), and hydrogen fluoride mixtures, we have observed repetitive superfluorescent pulses lasting 5–20 &mgr;sec. Optical‐cavity measurements verify that optical gain is present throughout the pulse duration at wavelengths in the nitrogen first‐ and second‐positive band systems and in a hydrogen near‐infrared band system. It is believed that HF serves to maintain a population inversion for a longer period of time by providing preferential collisional deactivation of the lower laser levels.

ISSN:0003-6951    

DOI:10.1063/1.1654564

出版商:AIP    

年代:1973

数据来源: AIP