Alpha and Photodetector

Function and Applications

This alpha-particle detector is for detecting alpha radiation and determining its energy.

Benefits

If it is not necessary to determine the energy of the detected particles, the alpha detector can also be used as a counter tube to detect beta radiation.

When an alpha particle hits the detector, it interacts with the material inside the depletion layer and gives up all its kinetic energy. In the course of this process, a number of free charge carriers will be generated which is proportional to the primary kinetic energy of the alpha particle. The proportionality between the kinetic energy and the quantity of charge carriers produced is applicable for alpha particles because they do not penetrate very far into the material. This is not the case for beta particles, since they penetrate into the material beyond the thickness of the depletion layer, too far for them to give up all their energy there. For beta particles, therefore, the detector can only be used to detect the entry of a particle and cannot establish its kinetic energy.

Equipment and Technical Data

• Sensitive surface: 15 mm².
• Energy resolution for alpha particles at 5.486 MeV: 30 keV.
• Required biasing: - 8... -38 V.
• Detector dimensions (length x diameter): 51 mm x 22 mm.
• Screen dimensions (length x diameter): 70 mm x 45 mm.
• Weight of detector: 55 g approx.
• Weight of screen: 35 g approx.
• The detector is supplied with a protective cap and a screen to keep out visible light.