摘要:

Photodiodes in thin films of epitaxial PbTe grown on BaF2have been fabricated using Sb+ion implantation to create ann‐type layer inp‐type films. At 77 °K, 15‐mil‐square diodes had typical zero‐bias resistances of 1 M&OHgr;. With the infrared radiation incident on then‐type implanted layer, peak detectivities at 5.3 &mgr;m of 4.5 &khgr; 1011cm Hz1/2/W were observed in reduced background. Quantum efficiencies were typically 55%. With the radiation incident on thep‐type side through the BaF2substrate, the detectivity was much more sharply peaked with the peak occurring at 5.5 &mgr;m. The peak detectivity and quantum efficiency values in this case were similar to those for incidence on then‐type implanted layer.

ISSN:0003-6951    

DOI:10.1063/1.1654789

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Submillimeter laser action has been achieved in ammonia by Stark shifting vibrational absorption lines into resonance with a CO2laser pump. In two of the three observed cases the absorption line was between states of the same parity, i.e., forbidden in the absence of the applied Stark field. Stark tuning of a vibrational absorption into resonance with a pump laser line is a general technique which should greatly increase the number of stable cw submillimeter lines available at milliwatt power levels.

ISSN:0003-6951    

DOI:10.1063/1.1654790

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Laser‐produced plasmas are shown to have characteristics useful for high‐resolution subnanosecond x‐ray radiography. Plasmas produced by 3‐J subnanosecond 1.06‐&mgr;m laser pulses focused onto an Al target emit x rays(≳ 1.5 keV)from a 50‐&mgr;m‐diam volume in the order of 1 nsec. Such sources may be useful to probe other plasmas.

ISSN:0003-6951    

DOI:10.1063/1.1654791

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The thermodynamics of using laser heating in conjunction with magnetic compression in &thgr;‐pinch plasmas is discussed. It is shown that the minimum laser energy required to achieve a given plasma filling factor &Lgr; (ratio of plasma to plasma tube area) isElaser= &Lgr;2/3Eplasmaand that any filling factor up to &Lgr; = 1 can be achieved. The proposed schemes have important implications for either increasing the performance of standard &thgr; pinches or for replacing the single‐turn &thgr;‐pinch coil by a multiturn solenoid.

ISSN:0003-6951    

DOI:10.1063/1.1654792

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Holographic interferograms are shown of &thgr;‐pinch plasmas heated axially by 35 J of 10.6‐&mgr;m radiation. One hundred percent conversion of laser to plasma thermal energy is indicated by the resultant plasma expansion and inferred temperature increase from 10 to 65 eV. The heated plasma column is 10 cm long by 6 mm in diameter and at an electron density of about 5 × 1017cm−3. The laser heating process is seen to produce a self‐trapping density minimum on axis in contrast to the density maximum encountered in normal unheated &thgr; pinches. This has significant implications for the high‐density laser‐heated long‐solenoid approach to fusion.

ISSN:0003-6951    

DOI:10.1063/1.1654793

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The Rytov approximation for wave propagation in random media is generalized to include the effects of self‐focusing. Solutions are obtained which show how the intensity fluctuations, which are either initially present in the wave or which are induced by the random inhomogeneities in the media, grow catastrophically. These solutions may be used to obtain conditions on the homogeneity of the medium, or of the incident beam, for reduction or elimination of catastrophic self‐focusing in the medium.

ISSN:0003-6951    

DOI:10.1063/1.1654794

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

We have measured the lasing energy of optically pumped high‐purity GaAs from 2 to 300 K. Low‐temperature results show strong many‐body effects in the band‐to‐band lasing below the single‐particle band‐gap energy, and the high‐temperature data indicate that the lasing energy approaches the band gap measured by photoconductivity.

ISSN:0003-6951    

DOI:10.1063/1.1654795

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Refractive‐index‐versus‐wavelength data were determined from 509 to 633 nm for a number of bubble memory rare‐earth garnet films. Using these data, the film thickness of these materials can be determined with an accuracy of 1–1.5%.

ISSN:0003-6951    

DOI:10.1063/1.1654796

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Boron and phosphorus ions of 8‐MeV and 6‐keV energy, respectively, have been implanted into silicon single crystals to form an+‐n‐p+‐n‐n+structure. Tests of this duodiode nuclear detector system with 5.5‐MeV &agr; particles yielded resolutions of about 100 keV (FWHM).

ISSN:0003-6951    

DOI:10.1063/1.1654797

出版商:AIP    

年代:1973

数据来源: AIP