摘要:

The circuit described defines accurately the time of arrival of slow pulses. The circuit consists of a compensated delay univibrator generating a signal whose width increases with the input pulse height so that it ends at a time almost independent of the input trigger amplitude. The trailing edge of this signal shifts only 10 nsec when the input is varied from 0.5 to 10 V, and less than 5 nsec when it is varied between 1 and 9 V. The univibrator has been incorporated in a simple fast‐slow coincidence circuit. Resolving times (2&tgr;) of 10–30 nsec have been obtained with Co60and NaI detectors without losing coincident events.

ISSN:0034-6748    

DOI:10.1063/1.1718192

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

The sensitivity and the signal‐to‐noise ratio of electrically deflected measuring instruments, such as magnetometers or galvanometers, can be increased significantly by reversing the exciting current periodically at the fundamental resonance frequency of the suspended system and observing the peak amplitude of the oscillatory dynamic deflection. If these current reversals are made to occur exactly at the midpoints between successive zeros of deflection, the oscillations of the suspended system will be stably maintained at the resonance frequency with a ratio of dynamic to static deflection of approximately 4/&dgr;, where &dgr; is the logarithmic decrement for free oscillation. This note describes electronic apparatus devised for controlling automatically the required quadrature timing of the current reversals. The circuits comprise a photocell‐actuated Schmitt trigger, a bistable flip‐flop, a timing capacitor, and a voltage comparator. Small timing errors due to finite slit width and hysteresis in the voltage comparator are of opposite sense and can be made to cancel.

ISSN:0034-6748    

DOI:10.1063/1.1718193

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

Surface barrier detectors operated at temperatures below 4.2°K are found to be sensitive to beta radiation throughout the volume of the silicon wafer and to give good resolution for conversion electrons (8.3 keV FWHM at 482 keV). The pulse height and resolution for a 1‐mm‐thick wafer are found to improve slightly with increasing reverse bias in the region of 300 to 530 V.

ISSN:0034-6748    

DOI:10.1063/1.1718194

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718196

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718198

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718199

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718200

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718202

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718203

出版商:AIP    

年代:1963

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718204

出版商:AIP    

年代:1963

数据来源: AIP