DESCRIPTIONS OF EXPERIMENTS for NE 104A

Spring 2009

No.	Title/ Date	Description
1	Oscilloscopes and pulse-detection electronics Feb 2, 4; 9 ,11	This experiment teaches the use of an oscilloscope and a pulse generator for signal tracing and measurements, and the use of pulse electronics components. The charge-sensitivity of a preamplifier-amplifier combination are studied in detail. Circuit noise and its charge equivalent are measured. Other counting circuit components are studied more briefly: discriminator, scaler, countrate meter.
2	Geiger counters Feb 18*, 20 (groups a and b) Feb 25, 27 (groups c and d)	A Geiger counter is used to observe the properties of gas counters in the proportional and Geiger-Müller (G-M) regions. The G-M plateau is measured and dead-time is measured by the two-source method.
3	Silicon semiconductors detectors Feb 18*, 20 (groups c and d) Feb 25, 27 (groups a and b)	A silicon detector is used to investigate diverse aspects of nuclear counting: (1) absorption of beta particles (intensity vs. absorber thickness) and the endpoint of the beta spectrum, (2) counting statistics and the distribution of a set of repeated measurements of counting rate, (3) radioactivity decay, multiscaling, the measurement and graphical analysis of a complex decay curve (Ag-108 + Ag-110 produced with Pu-Be neutrons on natural silver).
4	Stopping power for alpha particles Mar 3, 5 (groups a and b) Mar 10, 12 (groups c and d)	This experiment teaches multichannel analysis of a spectrum and the measurement of stopping power. A thin silicon alpha detector and an Am-241 source are used to obtain the range and stopping power of helium and argon for alpha particles, by measurement of the energy shift as a function of gas pressure. The detector window thickness is estimated by measurement of the energy shift when the detector is rotated so that the alpha particles impinge at an oblique angle.
5	Ge gamma-ray spectroscopy Mar 3, 5 (groups c and d) Mar 10, 12 (groups a and b)	This experiment teaches the characterization and the use of a high-purity germanium detectors to measure and analyze complex gamma spectra. Multichannel analyzers will be used to acquire energy spectra. Computer programs are used to obtain the energy and efficiency calibration of a Ge detector. The response of Ge detectors to gamma radiation will be discussed in detail. The Fano factor of Ge detectors will be determined experimentally.
6	Gamma-ray coincidences, timing resolution, and Compton scattering kinematics Mar 3, 5 (groups c and d) Mar 10, 12 (groups a and b)	This experiment teaches to measure timing resolution based on measurements employing germanium detectors and explores the Compton scattering kinematics. For both experiments, a germanium detector is operated in coincidence with a fast plastic scintillation detector. The timing resolution will be studied as a function of deposited gamma-ray energy. The same setup will be used to measure the energy dependence and the cross section of the Compton scattering process as a function of the gamma-ray scattering angle. Experimental results will be compared with theoretical predictions of the Compton scattering and the Klein-Nishina formula.
7	Neutron activation analysis Mar 17, 19	This experiment teaches the advanced use of a high-purity germanium detector multichannel spectrum analyzer to measure a complex gamma spectrum, and the use of gamma spectroscopy to identify components of a mixture of radioisotopes. A neutron-irradiated sample will be measured to determine the composition of this sample. Advantages and limitations of this neutron activation analysis will be discussed.
8	Neutron Detection Mar 31, Apr 2	Students will perform neutron counting using various neutron detectors such as BF-3 counters, He-3 detectors, and Fission counters. The specific responses of each detector to thermal and non-thermal neutrons will be discussed.
9	Neutronics Experiments Using a Subcritical Assembly Apr 7, 9	Students will measure the approach to criticality, selected neutronics parameter such as neutron flux shape, diffusion length, slowing-down length, and perturbation by strong neutron absorber.
10	Field trip to McClellan Nuclear Radiation Center Saturday, April 19, 8:00 - 4:00	Students will tour the facility (top of pool/control rod drives, sample preparation and chemistry labs, counting lab, control room) and do two experiments: (1) neutron flux measurements by activation analysis; (2) neutron cross section measurements.

  * This laboratory section is on a Tuesday, because Monday is a holiday.