REVERSIBLE GAIN VARIATIONS OF PHOTOMULTIPLIERS BY CHANGE IN COUNT RATE

Journal Article · Tue Nov 01 04:00:00 EST 1960 · Nuclear Instr. & Methods

DOI:https://doi.org/10.1016/0029-554X(60)90090-2· OSTI ID:4100047

Jung, H; Panussi, Ph; Janecke, J

The time dependence of the gain of several RCA, DuMont, and EMI photomultiplier tubes was measured prior to, during, and after a constant illumination of the photocathode. The light source was a NaI(TI) crystal irradiated with rays of Cs/sup 137/ or Co/sup 60/. A change in the counting rate resulted in rapid and slow variations in the gain. The rapid gain variations took place within an interval of less than 10 sec. The amplitude was dependent upon the change in counting rate and the tube chosen. The sign could be positive or negative for individual tubes of the same type. It was assumed that a sudden reversible sensitization or desensitization of the photocathode explains the effect. The slow gain variations after a change in counting rate were made up of two exponential components. The respective saturation value after an increase in counting rate was approached faster than after a decrease in counting rate. The amplitude was dependent upon the average anode current and the high voltage. It was assumed that reversible dynode effects explain the changes in gain variations. The different behavior of the various types of photomultiplier tubes is not correlated to the dynode material. The absolute value of the gain variations of all tubes examined were approximately of the same magnitude under comparable conditions. (auth)

• Research Organization: Max-Planck-Institut fur Kernphysik, Heidelberg, Ger.
• NSA Number: NSA-15-009114
• OSTI ID: 4100047
• Journal Information: Nuclear Instr. & Methods, Journal Name: Nuclear Instr. & Methods Vol. Vol: 9
• Country of Publication: Country unknown/Code not available
• Language: German

Related Subjects

CATHODES
DYNODES
ELECTRIC POTENTIAL
ENGINEERING AND EQUIPMENT
LIGHT
PHOTOELECTRIC EFFECT
PHOTOMULTIPLIERS
SCINTILLATION COUNTERS
SENSITIVITY
SODIUM IODIDES
THALLIUM