After-pulse suppression for 8850 and 8854 photomultipliers. [Due to gamma flash in neutron time-of-flight experiment]

Conference · Wed Oct 01 04:00:00 EDT 1975 · Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States)

OSTI ID:7355167

Lamaze, G P; Whittaker, J K; Schrack, R A; Wasson, O A

Spurious pulses occurring after large light output events in a scintillator (after pulsing) have been observed in semi-conducting first dynode photomultipliers (RCA 8850 series). The after-pulsing apparently has two components, an isochronous component occurring at a fixed time interval after the initial light pulse and an asynchronous component with a long duration lasting at least 40 ..mu..sec. The time interval between the isochronous bursts is related to the types of residual gases in the photomultiplier. In the RCA 8850 series tubes, the asynchronous after-pulsing consists of very low amplitude pulses and appears to be primarily due to single electron events, the number of these events being related to the main pulse amplitude. To obtain after pulse suppression, a fine stainless steel mesh was stretched tightly over the glass window of the photocathode. The mesh was then pulsed (FWHM = 250 ns) during the light flash to +300 volts relative to the photocathode potential. The isochronous and asynchronous afterpulsing was completely suppressed. Further details are presented.

• Research Organization: National Bureau of Standards, Washington, DC
• OSTI ID: 7355167
• Conference Information: Journal Name: Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States) Journal Volume: 1
• Country of Publication: United States
• Language: English

Related Subjects

440101* -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
MEASURING INSTRUMENTS
NEUTRON SPECTROMETERS
NOISE
PHOTOMULTIPLIERS
PHOTOTUBES
PULSES
RADIATION DETECTORS
SCINTILLATION COUNTERS
SPECTROMETERS
TIME-OF-FLIGHT SPECTROMETERS