Table of Contents

Scintillation counter

Scintillation counter
founder: pinky
depends on:
interested: pinky
ray
software license: -
hardware license: BSD

~~META: status = terminated &relation firstimage = :project:radiation_measurement.png ~~

Sensitive detector of radiation (mainly beta and gamma).

Brmlab's scintillation radiation detector.

TODO

Schematics and specifications

Schematic - connecting photomultiplier tube to hi-voltage source and output.

Building workflow

Step 1 - polishing FAG

Polished FAG - scintillation plastic blue glow of FAG in UV radiation

FAG, the block of plastic used as scintillator, it's surface contained some unevenness from cutting process.

The goal of polishing is to make the surface flat and transparent. Abrasion was made by sanding and then polishing paste. All abrasion was made with water due to cooling. But some overheating was not avoided and minor fractures occured.

Polished FAG glows nice in UV radiation, red LASER added for effect.

Step 2 - wrap FAG in aluminium

FAG wrapped in aluminium FAG wrapped in more aluminium FAG wrapped in aluminium and black ducktape FAG wrapped in aluminium and light-proof black plastic

Polished FAG was wrapped into aluminium foil (2 layers) and black plastic plastic (2 lyers) using black sellotape. On the top remains a hole for photomultiplier.

Step 3 - framing

Scintillation counter frame Scintillation counter frame

Finished scintillator with shielding was put into prepared frame. Frame is made from threaded rod and plastic part printed on RepRap.

Step 4 - attaching photomultiplier

Photomultiplier fitted into frame glued with bitumen. Photomultiplier cover attached. Top cover of photomultiplier with plugs for feeding and pulse counting.

Photomultiplier is attached to the scintillation plastic by some kind of very viscous silicone oil in order to keep good optical contact. Bitumen was put betwen the frame and photomultiplier, it keeps the photomultiplier in place and stops any light from outside. Last step was imbed covering tube for photomultiplier, this was made from metal drain pipe. Final step is attaching electronic interface and top cover. All wraped in black sellotape.

Step 5 - testing

osciloscope when only background radiation is present osciloscope when small sample of pitchblend is 30cm away from detector, approx. 1800 Bq (Hz)

Laboratory source of high voltage was attached and set to approx. 1400V. Osciloscope was attached for measurement. As source of radiation we used a small piece of pitchblend (few grams in weight). It was positioned 30cm from detector. The result is impressive. Further tests are in progress.