Alpha Spectrometer

Recently the applications of radioactivity in the industry and medical fields are on the rise in India, but the education in this field is mostly restricted to theory because the required experimental facilities are scarce due to the high cost of the equipment and difficulties in obtaining radioactive sources. For teaching, we need reliable, easy to maintain and inexpensive equipment, not the state of the art ones. The Alpha Spectrometer developed at Inter University Accelerator Centre is such a device. The Alpha Spectrometer consists of a small vacuum chamber, Pre-Amplifier, Shaping Amplifier and a 512 channel MCA with USB interface. The unit is powered by a 12V DC adapter.

Mechanical outline of the Alpha Spectrometer, Vacuum chamber, Detector and Electronics.

The vacuum chamber has an inner diameter of 80mm and a height of 30mm.

Vacuum chamber, with the PN Junction detector.     Pre-Amp, Shaper Circuits. 


The Shaping amplifier output, a Gaussian shaped pulse in the 0 to 5V range, is available on the BNC connector. This is fed to the MCA for generating the spectrum. The MCA has a USB interface and also it is powered by USB. A photograph of the MCA and energy spectrum of 241Am are shown below.


Like the other products from the Phoenix Project of IUAC, these designs are freely available for production, without any royalty. The software is under GPL and hardware is under CERN OHL. Resources required for making the Alpha spectrometer:

bpajith at
Oct 2016