摘要:

This letter gives experimental verification of Burgess' theory of the flux‐flow noise spectrum in Type II superconductors. The measurements made on vanadium foil biased in linear V‐I region shows quantative agreement with the modified theory.

ISSN:0003-6951    

DOI:10.1063/1.1653251

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The operation of an image storage panel, which is read in by means of optical absorption and read out in visible light by means of the Pockels electro‐optic effect, has been demonstrated. The sensing, storing, and readout medium consists of a single‐crystal film of cubic ZnS coated with a blocking contact. Performance characteristics observed to date on devices with areas between 1 and 2 cm2are resolution of 85 line pairs/mm, continuous visible readout for 1 h, and image storage for up to 100 h. The readin sensitivity to achieve a 2:1 contrast ratio in readout is 20 erg/cm2.

ISSN:0003-6951    

DOI:10.1063/1.1653252

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A new scheme for optically exciting high‐amplitude Rayleigh waves is described. The interference of two high‐power laser beams on a metallic surface produces periodic heating and a Rayleigh wave. The surface motions diffract the two laser beams, andID∝ IL3. These surface motions were as high as 200 Å at 30 MHz. Rayleigh waves have also been observed at 800 MHz, using a modulated laser for excitation.

ISSN:0003-6951    

DOI:10.1063/1.1653253

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The dose‐depth profiles for electrons extracted from a pulsed electron beam machine have been studied using a castable radiation‐sensitive plastic. These profiles exhibit a pronounced range shortening at charge fluences greater than 0.5 &mgr;C/cm2which reaches a limiting value, corresponding to a limiting internal field, at fluences greater than 1 &mgr;C/cm2. This behavior is interpreted in terms of charge build‐up and relaxation by radiation‐induced conductivity in the host material, poly(vinyl toluene). Positive charge‐trapping additives reduce this conductivity and allow the internal field to build up at lower charge fluences. The ratio of radiation‐induced conductivity to dose rate derived from these measurements 1.6 × 10−18sec/&OHgr;‐cm rad compares favorably with the value found at low dose by direct measurement of 3.0 × 10−18sec/&OHgr;‐cm rad.

ISSN:0003-6951    

DOI:10.1063/1.1653254

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Measurements show that single‐mode waveguides can be constructed which have radiation losses of about 7 dB/km—very close to the intrinsic material scattering loss. These waveguides, with total losses between 60 and 70 dB/km, have permitted the measurement of bending losses which become dominant at radii of curvature of a few centimeters. An approximate theory based on bending a rectangular guide appears to represent the circular waveguide results very well.

ISSN:0003-6951    

DOI:10.1063/1.1653255

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A study ofp‐type silicon shows that (1) the annealing temperature of electron‐irradiation damage increases as the acceptor concentration increases and (2) the isochronal annealing behavior of damage in samples with gallium and aluminum impurities is different from that in boron‐containing samples, which show a higher annealing temperature.

ISSN:0003-6951    

DOI:10.1063/1.1653256

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Surface barrierp‐njunction diodes made from high‐purityn‐GaAs grown by liquid‐phase epitaxy, have been operated as &agr;‐particle and low‐energy &ggr;‐ray detectors over the range 77–373°K. Resolutions observed were 1.2 and 2.95 keV (FWHM) at 130 and 295°K, respectively, for 122‐keV &ggr; rays and 30 keV for 5.47‐MeV &agr; particles. The energy per electron hole pair for &agr; particles is 4.51 eV and the Fano factor for &ggr; rays is ≤0.24 at 130°K.

ISSN:0003-6951    

DOI:10.1063/1.1653257

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

By a modified Bridgman solution‐growth technique employing a small temperature gradient. InP and GaP source crystal are used to saturate an In solution at ∼ 925°C and grow In1−xGaxP (x∼ 0.3) at ∼ 925°C. This material is shown to exhibit stimulated emission.

ISSN:0003-6951    

DOI:10.1063/1.1653258

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The pulse height response for &agr; particles incident upon Aun‐type CdTe surface barrier counters has been investigated. The energy required to form an electron‐hole pair in this material, by comparison with the specific energy loss per pair in silicon detectors, was found to be 4.46 eV at 300°K and 4.75 eV at 77°K.

ISSN:0003-6951    

DOI:10.1063/1.1653259

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Laser emission on five lines near 8 &mgr; has been obtained from a flowing mixture of H2&sngbnd;C2H2&sngbnd;He under pulsed electrical excitation. This emission has been tentatively identified asQ‐branch lines of the01000&Sgr;g+−000011&Pgr;uband(v2−v51)of C2H2. Pumping of the C2H2appears to result from a near‐resonant vibrational energy transfer fromH2*(v=1)which has been excited in a He‐rich discharge.

ISSN:0003-6951    

DOI:10.1063/1.1653260

出版商:AIP    

年代:1970

数据来源: AIP