摘要:

High‐energy atomic beams with Mach numbers as high as 5 were observed in excimer laser‐superconducting target interactions. The velocity distributions of the Y, Ba, Cu, and O atoms and ions could be described very well by a supersonic expansion‐type mechanism similar to a molecule beam. The physics of the atomic beam formation process is discussed.

ISSN:0003-6951    

DOI:10.1063/1.101553

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A design analysis is given for a bolometric infrared detector that uses the resistive transition of a high‐temperature superconductor as the temperature sensing element, and liquid nitrogen (LN) as the coolant. It is shown that for highly orientedc‐axis films, the measured low‐frequency noise causes little or no degradation of the performance. With the incoming radiation chopped at 10 Hz, noise equivalent powers (NEP) in the range (1–20)×10−12W Hz−1/2should be achievable. These values compare favorably with the NEP of other detectors operating at or above LN temperatures for wavelengths greater than 20 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.101447

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A Fresnel zone plate lens, with a nominal outer zone width of 400 A˚, has been used to image nanostructures with soft x‐ray synchrotron radiation at 45 A˚ wavelength with the Go¨ttingen x‐ray microscope at BESSY in Berlin. The structures, consisting of gold lines in thin silicon nitride membranes, were selected for tests of spatial resolution and image forming capabilities. Several patterns associated with deep submicron electronic circuits were also imaged, showing clearly resolved features smaller than 0.1 &mgr;m. Images of periodic structures, including 600 A˚ lines on 2000 A˚ centers, suggest a spatial resolution approaching the theoretical limit of approximately 500 A˚.

ISSN:0003-6951    

DOI:10.1063/1.100990

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Zeeman interferometry, based on the two‐frequency Zeeman effect laser, can be used for simple, noncontact differential thermometry. The thermometry is differential in both space and time. Small (0.73 &mgr;l ) laser‐heated volumes were monitored with a Zeeman interferometer. Heating rates varied over six orders of magnitude from 180 &mgr;K/s to 330 K/s. Temporal resolution was 10 &mgr;s. Measured temperatures and measured rates of heating were compared with theory for slowly and rapidly heated samples, respectively.

ISSN:0003-6951    

DOI:10.1063/1.100991

出版商:AIP    

年代:1989

数据来源: AIP