The work is dedicated to the discussion of the possibility of creating a position-sensitive detector
with both high coordinate reconstruction and time resolution. The work is presented the simulation
results and the experimentally obtained data for a prototype detector on the basis of
a multianode PMT MA-20 and a linear assembly of scintillating crystal or plastic strips.
The multianode position-sensitive PMT MA-20 has a semitransparent bi-alkaline photocathode
with the size of the sensitive area of $10 \times 200\ mm ^2$, 20 evaporated type bi-alkaline
dynodes of the same length and 20 separate anodes.
An assembly of scintillating strips made of GSO (gadolinium orthosilicate) crystals
with an element size of $3 \times 10 \times 50\ mm^3$, or of BGO (bismuth germanate)
crystals with an element size of $5 \times 15 \times 40\ mm^3$ also, and finally
set of plates made of a plastic scintillator
were used for experimental measurement of a coordinate resolution of the detector
prototype. Coordinate resolution was determined by the position of the center
of gravity of charges from neighboring dynodes.
The use of a multi-anode photomultiplier in combination with the array of crystal or plastic scintillators allows one to get the detector with a high performance in both
spatial and time resolution and also a low level of intrinsic noise in comparison,
for example, with silicon PMT’s. An ideal resolution simulation was performed for
a system consisting of a one-dimensional array of scintillation strips.
The experimental dependencies of the signal value versus position of optical
fiber with a diameter of 1 mm on the photocathode of the 20 anode PMT were also
measured. As a result of
processing the collected data, space resolution was obtained
at level of $\pm 0.7\ mm$, with a time resolution of
around $\pm 1.0\ ns $.
|Institute||NRC “Kurchatov Institute” – IHEP|