| 1. |
- Iacobaeus, C., et al.
(författare)
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A high position resolution X-ray detector : An Edge on illuminated capillary plate combined with a gas amplification structure
- 2006
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Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 53:2, s. 554-561
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Tidskriftsartikel (refereegranskat)abstract
- We have developed and successfully tested a prototype of a new high position resolution hybrid X-ray detector. It contains a thin-wall lead glass capillary plate converter of X-rays combined with a microgap parallel-plate avalanche chamber operating in various gas mixtures at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0-90 degrees. The detection efficiency, depending on the geometry, photon's energy, incident angle and the mode of operation was between 5-30% in single step mode and up to 50% in a multi-layered combination. Depending on the capillary's geometry, the position resolution achieved was between 50-250 mu m in digital form and was practically independent of the photon's energy or gas mixture. The usual lead glass capillary plates operated without noticeable charging up effects at counting rates of 50 Hz/mm(2) and hydrogen treated capillaries-up to 10(5) Hz/mm(2). The developed detector has several important potential advantages over the exciting X-ray detectors and may open new possibilities for medical imaging, for example in mammography, portal imaging, radiography (including security devices), as well as many other applications.
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| 2. |
- Iacobaeus, C., et al.
(författare)
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An X-ray scanner based on an "edge on" illuminated capillary plate combined with a gas amplification structure
- 2004
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Ingår i: 2004 IEEE Nuclear Science Symposium Conference Record. ; , s. 489-492
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Konferensbidrag (refereegranskat)abstract
- We have developed and successfully tested a prototype of a new type of high position resolution X-ray scanner. It contains a thin wall lead glass capillary plate converter of X-rays combined with a microgap parallel-plate avalanche chamber operating in various gas mixtures at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0-90°. The detection efficiency, depending on the geometry, photon's energy, incident angle and the mode of operation, was between 5-30% in a single step mode and up to 50% in a multi-layered combination. Depending on the capillary's geometry, the position resolution achieved was between 50-250 μm in digital form and was practically independent of the photon's energy or gas mixture. The usual lead glass capillary plates operated without noticeable charging up effects at counting rates of 50 Hz/mm2, and hydrogen treated capillaries up to 10 5 Hz/mm2. Finally, a prototype of the X-ray scanner based on an "edge-on" illumination capillary plate was built and tested. The developed detector open new possibilities for medical imaging, for example in mammography, portal imaging, radiography (including security devices), crystallography and many other applications.
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| 3. |
- Iacobaeus, C., et al.
(författare)
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An X-ray scanner prototype based on a novel hybrid gaseous detector
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 573:02-jan, s. 61-64
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a prototype of a new type of hybrid X-ray detector. It contains a thin wall (few mu m) edge-illuminated lead glass capillary plate (acting as a converter of X-rays photons to primary electrons) combined with a microgap parallel-plate avalanche chamber operating in various gas mixtures at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0 degrees to 90 degrees. The detection efficiency, depending on the geometry, photon's energy, incident angle and the mode of operation, was between a few and similar to 40%. The position resolution achieved was similar to 50 mu m in digital form and was practically independent of the photon's energy or gas mixture. The developed detector may open new possibilities for medical imaging, for example in mammography, portal imaging, radiography (including security devices), crystallography and many other applications.
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| 4. |
- Periale, L., et al.
(författare)
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A study of the operation of especially designed photosensitive gaseous detectors at cryogenic temperatures
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 567:1, s. 381-385
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Tidskriftsartikel (refereegranskat)abstract
- In some experiments and applications there is need for large-area photosensitive detectors to operate at cryogenic temperatures. Nowadays, vacuum PMs are usually used for this purpose. We have developed special designs of planar photosensitive gaseous detectors able to operate at cryogenic temperatures. Such detectors are much cheaper than PMs and are almost insensitive to magnetic fields. Results of systematic measurements of their quantum efficiencies, the maximum achievable gains and long-term stabilities will be presented. The successful operation of these detectors open realistic possibilities in replacing PMs by photosensitive gaseous detectors in some applications dealing with cryogenic liquids; for example in experiments using noble liquid TPCs or noble liquid scintillating calorimeters.
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| 5. |
- Periale, L., et al.
(författare)
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Photosensitive gaseous detectors for cryogenic temperature applications
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 573:1-2, s. 302-305
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Tidskriftsartikel (refereegranskat)abstract
- There are several proposals and projects today for building LXe time projection chambers (TPCs) for dark matter search. Important elements of these TPCs are the photomultipliers operating either inside LXe or in vapours above the liquid. We have recently demonstrated that photosensitive gaseous detectors (wire type and hole type) can operate perfectly well, until temperatures of LN2. In this paper, results of systematic studies of operation of the photosensitive version of these detectors (combined with reflective or semi-transparent CsI photocathodes) in the temperature interval of 300-150K are presented. In particular, it was demonstrated that both sealed and flushed by a gas detectors could operate at a quite stable fashion in a year/time scale. Obtained results strongly indicate that they can be cheap and simple alternatives to photomultipliers or avalanche solid-state detectors in LXe TPC applications.
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| 6. |
- Periale, L., et al.
(författare)
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Successful operation of hole-type gaseous detectors at cryogenic temperatures
- 2004
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Ingår i: 2004 IEEE Nuclear Science Symposium Conference Record. - 0780387007 ; , s. 1147-1151
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Konferensbidrag (refereegranskat)abstract
- We have demonstrated that hole-type gaseous detectors, GEMs and capillary plates, can operate up to 77 K. For example, a single capillary plate can operate at gains of above 103 in the entire temperature interval between 300 until 77 K. The same capillary plate combined with Csi photocathodes could operate perfectly well at gains (depending on gas mixtures) of 100-1000. Obtained results may open new fields of applications for capillary plates as detectors of UV light and charge particles at cryogenic temperatures: noble liquid TPCs, WIMP detectors or LXe scintillating calorimeters and cryogenic PETs.
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| 7. |
- Periale, L., et al.
(författare)
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The development of gaseous detectors with solid photocathodes for low-temperature applications
- 2004
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 535:02-jan, s. 517-522
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Tidskriftsartikel (refereegranskat)abstract
- There are several applications and studies in fundamental research, which require the detection of VUV light at cryogenic temperatures. For these applications, we have developed and successfully tested special designs of gaseous detectors with solid photocathodes able to operate at low temperatures: sealed gaseous detectors with MgF2 windows and windowless detectors. We have experimentally demonstrated that both primary and secondary (due to the avalanche multiplication inside liquids) scintillation light can be recorded by photosensitive gaseous detectors. The results of this work may allow one to significantly improve the operation of some noble liquid TPCs.
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| 8. |
- Periale, L., et al.
(författare)
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The successful operation of hole-type gaseous detectors at cryogenic temperatures
- 2005
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Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 52:4, s. 927-931
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Tidskriftsartikel (refereegranskat)abstract
- We have demonstrated that hole-type gaseous detectors, gas electron multipliers and capillary plates (CPs) can operate at temperatures down to 77 K. For example, a single CP can operate at gains above 10(3) in the entire temperature interval between 77 and 300 K. The same CP combined with CsI photocathodes operates perfectly well at gains of 100-1000, depending on the gas mixture. The obtained results open new fields of applications for CPs as detectors of ultraviolet light and charged particles at cryogenic temperatures: liquid noble gas time-projection chambers, detectors for weakly interacting massive particles or liquid Xe scintillating calorimeters, and cryogenic positron-emission tomography.
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