Why are HPGe detectors important? High-purity germanium detectors (HPGe detectors) are the best solution for precise gamma and x-ray spectroscopy. Due to its higher atomic number, Ge has a much lager linear attenuation coefficient, which
Why are HPGe detectors important?
High-purity germanium detectors (HPGe detectors) are the best solution for precise gamma and x-ray spectroscopy. Due to its higher atomic number, Ge has a much lager linear attenuation coefficient, which leads to a shorter mean free path.
How much does a HPGe detector cost?
For a 100% relative efficient HPGe detector system with mechanical cooling, the current price is on the order of $75,000.
What is an HPGe detector?
Synopsis: High Purity Germanium (HPGe) is the only radiation detection technology that provides sufficient information to accurately and reliably identify radionuclides from their passive gamma ray emissions. HPGe detectors have a 20-30x improvement in resolution as compared to that of Sodium Iodide (NaI) detectors.
How does a HPGe detector work?
HPGe Detector – Principle of Operation High-energy photon passing through the detector ionizes the atoms of semiconductor, producing the electron-hole pairs. Under the influence of an electric field, electrons and holes travel to the electrodes, where they result in a pulse that can be measured in an outer circuit.
Why Liquid nitrogen is used in HPGe detector?
Cooling to liquid nitrogen temperature (-195.8°C; -320°F) reduces thermal excitations of valence electrons so that only a gamma ray interaction can give an electron the energy necessary to cross the band gap and reach the conduction band. Therefore, HPGe detectors are usually equipped with a cryostat.
What is NaI detector?
A 2×2 inch sodium iodide (NaI) detector will allow the user to identify the presence of Cs137 at < 1 urem/hr/sec. The 3×3 inch NaI detector can identify Cs137 at 500 nrem/hr/sec. This is why BNC’s SAM III generation and SAM 940 are designed to easily hold large detectors and operate them with one hand.
How does a germanium detector work?
Ionizing radiation enters the sensitive volume (germanium crystal) of the detector and interacts with the semiconductor material. High-energy photon passing through the detector ionizes the atoms of semiconductor, producing the electron-hole pairs.
Which of the following is the disadvantages of solid state semiconductor detector?
The disadvantage is that silicon detectors are much more expensive than cloud chambers or wire chambers. Degradation. They also suffer degradation over time from radiation, however this can be greatly reduced thanks to the Lazarus effect. High FWHM.
Why do germanium detectors need to be cooled?
Because germanium has relatively low band gap, these detectors must be cooled in order to reduce the thermal generation of charge carriers (thus reverse leakage current) to an acceptable level. Otherwise, leakage current induced noise destroys the energy resolution of the detector.
How are high purity germanium detectors ( HPGe ) cooled?
Because High Purity Germanium detectors (HPGe) has relatively low band gap, these detectors must be cooled down. Liquid nitrogen (LN2) or electromechanical cooling system are both available. The High Purity Germanium detectors (HPGe) complete set is composed by the following components:
What is the energy range of a HPGe detector?
10% – 50% efficiency HPGe detectors are available p and n type HPGe detectors coaxial and planar HPGe detector geometry Energy range from 40 keV to 10 MeV or extended energy range down to 3 keV Input window materials: Aluminium, Beryllium or Carbon-fiber
What kind of cooling system does a HPGe radiation detector use?
HPGe Radiation Detector Cooling ICS Integrated Cryocooling System Mobius Recycler Condensing Liquid Nitrogen Cooling System Dewars and Cryostats HPGe Radiation Detector Electronics HPGe Radiation Detector Options and Accessories
What kind of diodes are used in HPGe detectors?
All HPGe radiation detectors are just large, reverse-biased diodes.The germanium material can be either “n-type” or “p-type”.The type depends on the concentration of donor or acceptor atoms in the crystal.To connect the diode to an electrical circuit to amplify the