At present there is a strong need for high-sensitive non-cooled radiation detector materials for X- and gamma-rays suitable for biomedical and industrial applications.
What is best material for the development such detectors ?
I would consider CVD Diamond for the cooling paert and the radiation hardness.
There are drawbacks on the cost and on the surface you could cover.
I guess the question could be reposed as - which of the existing high resolution room temperature detector technologies is most amenable to scaling up of the crystal size. CZT is very good at low energies (sub 100 keV), however the crystals I've seen have been rather small so the efficiency drops off quickly above 100 keV . I understand the same problem exists with lanthanum halide.
The answer depends on the energy your are measuring.
For low gamma-ray energies (5 keV ... 60 keV), silicon detectors are excellent. They are available on the market at very low prices because they are used in enormous quantities around the big accelerators (LHC in CERN).
They are easy to use.
I think pure silica core optical fiber with high-OH content is suitable for designing radiation detectors. It is sensitive to radiation influence, at the same time provides good radiation resistance. But, pure silica optical fiber are effective at higher dose values
Do you need it for spectrometry or for ealuation of total dose? Or probably you would like to use it for imaging? Each of application has oun preference matherial.
It depends what do you mean with "high-sensitive" and in which range of energy you are interested.
Scintillation detectors such ad Na(I) or Na(Tl) are not not cooled and if well calibrated you can reach a reasonable measurement accurancy.
I guess that the question concerned the X- and gammma-ray spectrometry....
Not dosimetry.
My question relates to both radiation detectors, i.e. detectors which evaluate radiation dose and to scintillator detectors. More discussion - better !
Thee best scintillators for X-ray measurements are YAlO3:Ce and Y3Al5O12:Ce. They have good energy resolution up to 5keV. Moreover, they have moderate temperature dependence of LY up to 130C and can be used without T stabilization.
Best materials in terms of performance (whatever your performance criteria are) and price/performance can be quite different; e.q. YAL:Ce based detectors are much more expensive then CsI(Tl) detector of similar sensitivity and simply not available in large volumes. If the high sensitivity is achieved by increasing # of detectors or its sensitive volume the cost figure can define your choice of material.
You might want to consider Cd-Te (Cadmium Telluride) or Cd-Zn-Te (doped with Zinc) material. It is used in semiconductor type of detectors that can be operated at room temperature. Some vendors offer them with embedded Peltier (thermoelectric) cooler. Typically, these detectors are intended to detect X- or gamma-rays and they do so by direct measurement. The internal electric circuit employs comparators to filter the signal by energy using the pulse height information. That provides so called energy-resolving capability. Having that, one can suppress electronic noise by setting the lowest threshold higher than noise level (for example > 5 - 10 keV for diagnostic X-rays). Also these detectors can be used for spectrum measurements. I believe the energy resolution is in the order of few keV (again in X-ray diagnostic range) (typically 5% of incident energy), while HpGe detectors can provide eV resolution (but of course in expense of cryogenic cooling). NaI detectors for example can reach 5% resolution for much higher energies (around 2 MeV or so), and resolution for the lower energy is worse.
Depends what is the goal you are pursuing - for gamma or charged particles, spectrometric or not, energy range, backgound consideration etc.. For example - if gamma is to be measured, a "reasonable" energy range is considered (50-2000 keV) nad the background is matter (environmental samples) and the detector has to possess spectrometry properties I would advice CeBr scintillator based detector. It has reasonable good energy resolution, density and Z suitably to make the efficiency also good, can be produced in large volume crystals, does not have own activity and the price is affordable as well the accessibility. For any other application the goal and the constraints have to be clearly identified in order to make the right choice.
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