Speaker
Description
Since a long time ago, members of the High Energy Physics community have been using plastic scintillator paddles, coupled to a photomultiplier tube (PMT) as the detector for making a cosmic ray telescope to generate a cosmic ray muon trigger. One big drawback of such paddles has been the use of bulky photomultiplier tubes, which sometimes pose a great challenge in making a particular geometry. Not only are the PMTs bulky, but they also are quite expensive, require a high bias voltage as well as current, moreover, they cannot be used in the presence of even a tiny magnetic field.
Keeping this in mind, we designed and built a compact plastic scintillator paddle using SiPM for readout instead of a PMT. Extruded Plastic Scintillator (EPS) strips, manufactured in the Fermilab EPS factory were used. These strips have a top groove along the length for keeping the fibre. A Fibre Guide Bar (FGB) was designed to terminate the fibre at a pre-defined location exactly in front of an SiPM. The SiPM sits in a well in a specially designed SiPM Mounting Block (SMB) and a Counter Mother Board (CMB) is used as an interface between the SiPM and the front-end amplifier placed at a convenient location. The mechanical parts were manufactured in the TIFR central workshop. The paddles were assembled with Wavelength Shifting (WLS) fibres and SiPMs. A dozen paddles were prepared. After testing the paddles, it was found that all of them had a muon detection efficiency better than 99%.
For operating these paddles, front-end electronics was designed comprising of a 4-channel amplifier-discriminator card, a custom made SiPM bias generator, display and controller for the bias, and a low voltage power supply to operate these devices in the module. External NIM modules were used to form a cosmic muon trigger. This paper will discuss construction and characterisation of the scintillator paddles and the standalone electronics designed for them.
| Field of contribution | Experiment |
|---|
