I can think of three potential purposes for a spacer. The first is to fix the distance between the specimen and the detector - to make readings comparable from one to the next. The second is to protect the detector from becoming contaminated by the specimen. The third applies to reactor environments. Spacers are used there to displace whatever fluids (usually water or water solutions) are in the reactor.says said:I'm just reading over some experimental notes for neutron activation analysis and I see the mention of a spacer being placed between the irradiated sample and the detector face. What does a spacer actually do? I did a quick google but couldn't really find anything.
A spacer in neutron activation is a material, usually made of a non-reactive substance such as aluminum or graphite, that is used to separate samples from the neutron source during the activation process. This allows for a more controlled and efficient activation of the samples.
A spacer is necessary in neutron activation because it helps to reduce interference from the surrounding materials and allows for a more accurate measurement of the sample's activation. Without a spacer, the sample could be activated by neutrons from the surrounding materials, leading to inaccurate results.
A spacer can affect the results of neutron activation by reducing the background interference from the surrounding materials, allowing for a more accurate measurement of the sample's activation. It also helps to maintain a consistent distance between the sample and the neutron source, ensuring a more controlled activation process.
A spacer can be made from a variety of materials, but it is important to choose a material that is non-reactive to neutrons and will not interfere with the activation process. Common materials used for spacers include aluminum, graphite, and boron carbide.
The appropriate thickness for a spacer in neutron activation is determined by the energy of the neutron source and the desired activation level of the sample. Thicker spacers are typically used for higher energy neutron sources, while thinner spacers may be used for lower energy sources. The thickness can also be adjusted based on the specific needs of the experiment or analysis being conducted.