摘要:

The use of a combination of steady and pulsed dc biasing of a ZnO monolithic SAW device enabled a distinction to be made between surface‐state andpndiode storage mechanisms in a single memory correlator device. By use of demonstrated biasing schemes, storage times of from tens of microseconds to tens of miliseconds are available in a single device.

ISSN:0003-6951    

DOI:10.1063/1.90234

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Mass spectrometric analyses have been performed on the positive and negative species from discharges in Cs, He‐Cs, and He‐H2‐Cs mixtures. Sampling was conducted through the electrodes of normal glow discharges and from close‐spaced heated‐cathode conditions, which approximate a cesium thermionic converter. No negative Cs ions were observed for Cs pressures less than 10−2Torr. Identified species included Cs+, Cs+2, Cs−, and what appeared to be multiply charged ions. Low‐mass negative and positive ions attributed to H2were observed when an He‐H2mixture was also present in the discharge region.

ISSN:0003-6951    

DOI:10.1063/1.90235

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Transition radiation can be emitted by neutral‐charge structures, such as atoms, crossing the interface between dielectric media. Intensities in excess of 103photons/sec, in the energy range 1–50 keV, may be obtained from high‐power (≳100 kV, ≳1 A) beams of neutral hydrogen isotopes incident on foils. This effect may have practical implications for constructing energy‐sensitive monitors for intense neutral beams.

ISSN:0003-6951    

DOI:10.1063/1.90240

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Experiments are described in which field‐reversingElayers were transported axially in RECE‐Christa over a distance of up to 10 ring radii using time‐varying magnetic fields. When properly executed, this process does not lead to anomalous fast‐electron losses. The translation speed appears consistent with that expected from the interaction of the rings with the axialBz‐field gradients and the resistive tank wall. No significant difference is observed between moving the rings in a homogeneous H2fill and moving them from a transient gas cloud into a low‐gas‐density region.

ISSN:0003-6951    

DOI:10.1063/1.90241

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

As a novel alternative to existing means of preionization, we have used x radiation to preionize a high‐pressure KrF laser mixture and found that the x‐ray preionization produces a uniform glow discharge for high‐pressure KrF laser gas.

ISSN:0003-6951    

DOI:10.1063/1.90242

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A cw CO2laser is used to vibrationally excite CH2D2. IntentionalVTdeactivation competes with interisotopeVVtransfer and prepares a sample of gas in which the CH2D2is excited while the CH4remains unexcited on a steady‐state basis. Subsequent reaction of this mixture with chlorine atoms and molecules forms a stable product, deuterated methyl chloride, enriched in deuterium by up to 72%. Extension to the CH3D system will be discussed. A conservative estimate of the energy requirement for a commercial facility (natural abundance feed) based on the latter system gives a value within a factor of 4 of that required by the currently used H2O/H2S commercial process.

ISSN:0003-6951    

DOI:10.1063/1.90243

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have reacted thin Pt, Pd, and Ni films with single‐crystal Si usingQ‐switched Nd : YAG laser pulses of 100‐nsec duration in the power range 18–50 MW cm−2. The layers are laterally very uniform in thickness but are not single phase. Average composition of the reaction product layer can be changed over a wide range by varying film thickness and laser power. The microstructure of the reacted layers indicates that reaction occurs via surface melting, mixing, and rapid resolidification.

ISSN:0003-6951    

DOI:10.1063/1.90244

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

High‐quantum‐efficiency planar and mesa InGaAsP avalanche photodiodes have been fabricated by beryllium ion implantation. The implanted diodes, after suitable annealing, exhibited a very low dark current density of 4.0×10−6A/cm2at 10 V. The devices have 65% external quantum efficiency at 1.06 &mgr;m without an antireflection coating and a uniform avalanche gain of 12.

ISSN:0003-6951    

DOI:10.1063/1.90218

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have modified a transmission acoustic microscope by replacing the input lens with an optical counterpart. The input to this system comes from a mode‐locked andQ‐switched Nd : YAG laser at 1.06 &mgr;m. Acoustic signals arising from thermoelastic coupling are generated in metallic films at frequencies determined by the modulation envelope of the optical beam. The output acoustic lens and transducer responsive to sound waves at 840 MHz detect the acoustic energy which comes from the heated volume (∼2‐&mgr;m diameter) near the focal region. The sample is mechanically scanned through the focal point in a raster pattern to record the photoacoustic images. We suggest this as a method for collecting new information on microscopic structures.

ISSN:0003-6951    

DOI:10.1063/1.90219

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The time evolution of gain and absorption in an XeF laser discharge is studied using a pulsed uv dye‐laser probe and timing system with ±7‐nsec resolution. The dissociation rate of the lowest vibrational level of the XeF ground state as a function of helium buffer pressure is found to have a slope of 1×104sec−1 Torr−1(±15%).

ISSN:0003-6951    

DOI:10.1063/1.90220

出版商:AIP    

年代:1978

数据来源: AIP