Research: Activation

Research and Development: Activation Analysis

NaCl Delayed Gamma Activation Analysis (spectrum taken immediately after irradiation, and then repeated 8 hours later.
Tin half life 1Sn-123m and Sn-125m

Graph showing the half lives of two isotopes of Tin made by exposure to neutrons from one of our neutron generators.

These neutron generators are ideal for performing activation experiments in the classroom or as a research tool to identify materials. Delayed Gamma Activation Analysis (DGAA) is well suited to the classroom because a sample can be irradiated for a short period of time, and then data collected over several hours. This allows several students to productively use the same neutron generator.

Typical experiments

A sample can be irradiated by the neutron generator for a known period of time and then placed in front of, ideally, a gamma ray spectrometer or some other radiation detector such as a scintillation counter or a simple Geiger counter. The activity can be measured at successive time intervals following the removal of the source from the proximity of the neutron generator. The radiation levels can be compared with calibrated radioactive sources allowing nuclear cross sections to be estimated. The effect of thermalization, ie thickness of moderator placed between the fast neutron source and the sample, can be investigated as can the design of the shape and material (for example high density polyethylene or carbon – such as reactor grade carbon moderator). Advanced students can use the source in combination with numerical neutron modeling codes, to investigate real-world situations.

A list of simple experiments that we have activated using these generators is given below.

copper

aluminum

tin

indium

table salt - both sodium and Chlorine