Glossary

GLOSSARY

• Alpha spectrometry 
  The alpha spectrometry is the measuring technique that allows to identify (by energy values) and quantify (by number of counts) alpha emitting radionuclides by detecting the alpha particles not self-absorbed in the layer by a semiconductor detector under proper vacuum conditions.
  
  
• Background count
  The number of counts collected by a radiation detector from background radiation.
  
  
• Carrier
  In radiochemistry a carrier is a stable compound/chemical species with the same chemical behavior of the species containing the target radionuclide. Carrier is used for the prevention of adsorption/losses and specially to precipitate suitable radionuclides from solutions. It could be isotopic (containing a stable isotope of the target radionuclide) or non-isotopic (containing, in a suitable chemical form, a different stable element but with same chemical behavior of the radioactive target species).
  
  
• Chemical/Radiochemical recovery yield
  It helps in calculating the effective recovery of the target radionuclide: it is equal to the ratio between the amount/activity of carrier/tracer obtained after the separation with respect to the initially added one.
  
  
• Counting efficiency
  It is defined as the ratio between the counts measured and the decay events really occurred in the time unit.
  
  
• HPGe-detectors
  High Purity Germanium (HPGe) Radiation Detectors is a semiconductor detector used as gamma detector. Germanium semiconductor detectors have superior energy resolution compared to scintillation detectors.
  
  
• Liquid Scintillator Counting
  LSC is the method for measuring the radioactivity of hard to detect radioisotopes, mostly pure beta (beta minus and electron capture) also in presence of alpha-emitting isotopes. The radioactive sample is mixed with a scintillator cocktail that absorb the radiation energy by emitting detectable light pulses.
  
  
• Minimum detectable activity
  The minimum detectable activity is the level of activity which is practically achievable by an overall measurement method.
  
  
• Quenching
  Quenching is a decrease in the efficiency of energy transfer from the beta particles, for example, to the scintillator, and a decrease in light photon intensity before they reach the PMTs.
  
  
• Radiochemical purity
  The radiochemical purity is the fraction of the radionuclide of interest in the desired chemical form of the total radioactivity of the radionuclide in a radioactive sample.
  
  
• Tracer
  A tracer is a radioactive compound/chemical species with the same chemical behavior of the analyte containing the target radionuclide/s. The tracer is usually added to the sample with activity values of same order of magnitude of the target radionuclide/s.