Advanced Study Course

Section C

Experiment 2.3 – Alpha Spectroscopy with a Semiconductor Detector

Aim is to become familiar with a measurement system consisting of a semiconductor detector with subsequent electronics (charge-sensitve pre-amplifier, ulse-shaping main amplifier, analogue-to-digital converter and data storage) as well as with the fundamentals of the alpha decay.

Initially, an energy calibration with a pulse generator and a prominent alpha line from 241Am (whose energy is known) is performed. After application of this calibration, the energies of the other alpha lines in the spectrum are extracted and their relative intesities are determined. Taking into account the width of the line from pulse generator, the contribution to the total width of the alpha lines which does not orinate from electronic noise can be deduced.

In the second part of the experiment, the stopping power of alpha particles in air is measured.