LEVEL 3 LABORATORY

High Energy Physics

High Energy Electron SpectroscopyObjectives of the Project

• Determine the spectral energy distribution of beta radiation from a Sr/Y-90 source.
• Measure the spectrum at a variety of magnetic field settings.
• Investigate the absorption of beta particle energy by various metals.

Apparatus
 

• Beta radiation spectrometer box and vacuum system.
• Magnet, voltage controllable power supply and Hall probe.
• High voltage supplies.
• Solid state radiation detector.
• Electronics.
• Pre-amplifier.

Experimental Procedure

1. Determine the characteristics of the solid state detector with the beta source directly beneath the detector. Observe the effect of air pressure in the vacuum chamber on the beta spectrum.
2. Calibrate the magnetic field against the energising current using the Hall probes.
3. Do a rapid experiment to determine the optimum measurement time for each data point; at what fields do you need the most precise measurement?
4. Use your magnetic field results to calibrate the solid state detector’s energy scale.
5. Investigate the change in the energy spectrum when metal targets are placed between the beta particle beam and the solid state detector.

Safety and Precautions

The Sr/Y-90 source used this project has a relatively high activity and therefore should only be handled using appropriate tweezers.

References

• Siegbahn, K.: Alpha, Beta and Gamma Spectroscopy.
• Evans, R.D.: The Atomic Nucleus.
• Leo, W.R.: Techniques for Nuclear and Particle Physics Experiments
• Useful statistics

External links

• beta decay and the neutrino how beta spectroscopy can be used to better understand the weak interaction.