Table of Contents
Which detector has 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 energy resolution of gamma spectrometry?
The detectors have roughly equal efficiency and energy resolution for 662 keV gamma rays. At photon energies below 50 keV the energy resolution of a spectrometer system may be limited mainly by electronic noise (Knoll, 1989).
How does a Ge detector work?
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. This pulse carries information about the energy of the original incident radiation.
How do you calculate efficiency of a detector?
the efficiency of the detector for radiation from the sample must be calculated using formula ε(E) = ω ε0(E), finding the value of the coefficient ω for the relation (2). For a cylindrical container l = H and for a complex-shaped container l = H – h.
How does germanium detector work?
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.
Why the energy resolution of a semiconductor detector is better than gas filled detector?
The advantage of semiconductors is that the average energy required to create an electron–hole pair is ~ 10 times smaller than the one required for gaseous detectors and 100 times smaller than for scintillation detectors.
Why are germanium detectors 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.
Why does detector efficiency decrease with energy?
The efficiency decreases with increasing energy because the probability that the photon will interact within the detector also decreases with energy.
What is the efficiency of a detector?
“Detection efficiency” is defined as the ratio of the output signals to incident electrons, X-rays or photons to a detector (input signals). A detector with high detection efficiency meets various requirements, such as high conversion efficiency from input to output, short dead time, and low noise.
What is 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 is 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.
What are germanium detectors used for?
Since germanium detectors produce the highest resolution commonly available today, they are used to measure radiation in a variety of applications including personnel and environmental monitoring for radioactive contamination, medical applications, radiometric assay, nuclear security and nuclear plant safety.
Which type of detector is more sensitive to Gamma Radiation?
Geiger Counter
Detection of Gamma Radiation using Geiger Counter Geiger counter is therefore a much more sensitive device than other chambers. It is often used in the detection of low-level gamma rays and beta particles for this reason.
What is the resolution of the Bege detector?
This aspect of thin detector performance has long been recognized in applications such as actinide lung burden analysis. Most Low Energy Detectors are aptly named because they do not give good resolution at higher energies. In fact resolution is not usually specified above 122 keV. The BEGe detector represents a breakthrough in this respect.
Why choose Mirion broad energy GE (Bege) detector?
Thin, stable entrance window allows the detector to be stored warm with no fear of low energy efficiency loss over time The Mirion Broad Energy Ge (BEGe) Detector covers the energy range of 3 keV to 3 MeV like no other.
How does the Bege detector work?
The BEGe detector represents a breakthrough in this respect. The BEGe unit is designed with an electrode structure that enhances low energy resolution and is fabricated from select germanium having an impurity profile that improves charge collection (thus resolution and peak shape) at high energies.
What are the Bege detector and preamplifier energy rates?
The BEGe detector and associated preamplifier are normally optimized for energy rates of less than 60 000 MeV/sec. Charge collection times prohibit the use of short amplifier shaping time constants. Resolution is specified with an optimum shaping time constant and Lynx® digital peaking time equivalent.