What is a high purity germanium detector?

What is a high purity germanium 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.

What are the three types of semiconductor detectors?

Contents

• 2.1 Silicon detectors.
• 2.2 Diamond detectors.
• 2.3 Germanium detectors.
• 2.4 Cadmium telluride and cadmium zinc telluride 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.

Which detector has the best energy resolution?

Planar detectors usually achieve the best energy resolution, because of their low capacitance; they are preferred for detailed spectroscopy, such as the analysis of the complex low-energy gamma-ray and x-ray spectra of uranium and plutonium.

What is NaI detector?

A NaI(Tl) scintillation counter is a radiation detector which uses the effect known as scintillation. Scintillation, which occurs in the NaI(Tl) crystal, is a flash of light produced in a transparent material by the passage of a particle (an electron, an alpha particle, an ion, or a high-energy photon).

How does a scintillator work?

How do they work? Scintillators are a group of materials that luminesce when exposed to ionizing radiation. In layman’s terms that means these materials emit light when they absorb particles or electromagnetic waves that create “free” electrons in the material.

What are scintillation detectors used for?

Scintillation detectors are used for the determination of the high-energy part of the X-ray spectrum. In scintillation detectors the material of the detector is excited to luminescence (emission of visible or near-visible light photons) by the absorbed photons or particles.

What is a germanium detector?

Germanium detectors are semiconductor diodes having a p-i-n structure in which the intrinsic (i) region is sensitive to ionizing radiation, particularly x rays and gamma rays. Under reverse bias, an electric field extends across the intrinsic or depleted region.

Why is germanium used in the PN junction for Nuclear Detector?

In gamma spectroscopy, germanium is preferred due to its atomic number being much higher than silicon and which increases the probability of gamma ray interaction. Moreover, germanium has lower average energy necessary to create an electron-hole pair, which is 3.6 eV for silicon and 2.9 eV for germanium.

How do scintillators work?

What is energy resolution of scintillation detector?

Energy resolution of scintillation detectors used in gamma-ray spectroscopy is often dictated by the number of cathode electrons in the associated photo-multiplier tube (PMT). BGO energy resolution is projected to improve from the current best value of 10% at 0.662 MeV to about 6% (FWHM).

Which detector has very good resolution and efficiency?

High purity germanium detector has better resolution compared to the scintillation type of detector, Sodium iodide (NaI). The HPGe detector offers the advantage of resolving two closely located energy points and has the ability to detect a mixture of nuclear material.

Can a germanium detector be used as a HPGe detector?

While silicon-based detectors cannot be thicker than a few millimeters, germanium can have a depleted, sensitive thickness of centimeters, and therefore can be used as a total absorption detector for gamma rays up to few MeV. Cooling. The major drawback of HPGe detectors is that they must be cooled to liquid nitrogen temperatures.

Which is more efficient germanium or silicon detector?

In comparison to silicon detectors, germanium is much more efficient than silicon for radiation detection due to its atomic number being much higher than silicon and due to lower average energy necessary to create an electron-hole pair, which is 3.6 eV for silicon and 2.9 eV for germanium.

Which is part of germanium detector is sensitive to gamma rays?

Germanium detectors have a p-i-n structure in which the intrinsic (i) region is sensitive to ionizing radiation, particularly X rays and gamma rays. Under reverse bias, an electric field extends across the intrinsic or depleted region.

What’s the difference between HPGe and NaI detectors?

HPGe Detectors vs NaI (Tl) Scintillation Detectors. For gamma spectrometry, the most common detectors include sodium iodide (NaI) scintillation counters and high-purity germanium detectors. Radiation Dosimetry