Can anybody suggest me a good energy dispersive X-ray detector with high resolution and wide range (1 keV- 100 keV)? Actually, we need a detector to detect a wide range of elements in a single run using PIXE or EDXRF technique.
I suggest one of the detectors of AMPTEK (mod. XR100 or X123). Depending on the energy range, you can choose Silicon-based or CdTe-based detectors. However, efficiency won't be optimized in the whole 1-100 keV range, so you're forced to find a trade-off.
Silicon-based devices are optimized for working in the range 1 - 30 keV, whereas CdTe detectors work better in the range 5 - 150 keV. However, in case of CdTe detectors, a good efficiency down to 2-3 keV can be obtained by using a thinner Be window.
Resolution is 1.2 keV @ 122keV (57Co) for CdTe detectors and 125 eV @ 5.9 keV (55Fe) for Silicon detectors.
For futher details: http://www.amptek.com/
Marco is right, the Amptek is a good choice. We have several of them in more or less daily use, for laboratory use with X-ray sources and radioactive sources as well as for Synchrotron applications, in vacuum, in ambient air, in protecting gases. The XR100 is affordable, and may be operated under different software environments such as windows, linux, spec. Low as well as high energies may be detected with one single detector, see e.g. the example with a Co57 source with an gamma line at 122 keV with ca. 500 eV resolution, or the XRF spectrum of a high TC superconductor (Y-Ba-Cu-Oxide) excited with a Cu anode. There the Ba L-lines between 4.4 and 5.2 keV are clearly resolved. I would recommend the XR100SDD, as it allows much higher count rates compared to the standard diodes. Hope this gives you an idea - don't hesitate to ask for more details, Dirk
Had the original question been "Can anybody suggest me a good energy dispersive X-ray detector to detect a wide range of elements in a single run using PIXE or EDXRF technique.?" I would have understood the requirements and holeheartedly endorsed the Amptek as mentioned by the first two respondents: maybe the Oxford unit is good too. But, what gave me pause is the middle part of the question "... with high resolution and wide range (...).... ". This specification is quantitative only in the range, 1 keV- 100 keV, but not in the energy resolution: this is only a qualitative 'high'.
Why? much higher energy or wave length resolution can be obtained over the energy region where it might be most useful, maybe 1 to 30 keV, by combining the Amptek sensor with a wave length dispersive crystal, as has recently been done by J. Seely and others.
I should have added the paper that shows how energy resolution can be improved with a wave length dispersive crystal. It is in section 3, and figures 4 and 5, of the attached paper.
Hi, I've used the Amptek silicon drift detector X-123 SDD, which is quoted as having a FWHM of 136 eV at 5.9 keV. It is great for low energies, but starts becoming quite inefficient above 40 keV or so, but the Amptek website has correction factors. I am not sure if it goes to 100 keV (maybe with the thicker entrance window?), but it might be worth looking into. It connects to PC with a USB cable... I attached a spectrum I measured of an I-125 seed to give you an idea of the energy resolution. Hope this helps!
Hi,
1. The SDD detectors (e.g. Ampek) is a very good, fast counting detector but not efficient at higher energies, as told above. Using a thicker window will not solve a problem, but stop the low energies.
2. The "old fashion" Si(Li) detectors will certainly have improved efficiency at higher energies, but not sure if enough to go to 100 keV. But than the count rate will be reduced (some 10 - 15 kcps).
3. Consider combination of 2 detectors or WD detection (with crystal).
4. Consider detection of hig-Z elements based on L-series lines - the maximal energy will be at not more than 25 keV for heaviest elements.
5. For low energy end of your range consider the detector with the thinnest window, you should also use vacuum (He atmosphere) to avoid absorption of your signal on the way to the detector.
Si based detectors will be advantageous up to about 20keV. After that the efficiency will drop dramatically. You may use Ge detectors (LeGe, ULeGe) and CdTe detectors but you should consider your analytical problem since you may suffer from the presence of escape peaks. The best solution would be a combination of both Si, Ge detectors with appropriate filters in mirror geometry. It depends on your budget.
Dear Dr. B. Mallick
Have a nice day
@Marco Girolami
yes, as Dr. Marco Girolami suggested before, you can use the detectors of AMPTEK (mod. XR100 or X123) and you can choose Silicon-based ( in the range 1 - 30 keV) or CdTe-based ( in the range 5 - 150 keV) detectors according to the required to do.
Good luck
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