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Jet-X at MSSL |
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MART-LIME |
MART-LIME is being build by IAS in collaboration with IKI. The base-line photon detection system of MART-LIME is a high pressure (5 bar) Xenon-filled MWPC behind a coded mask aperture. The MWPC will be sensitive to energies 5-150 keV with an efficiency higher than 10%. The background rate will be substanstially reduced through a fluorescence gated coincidence mode wherein events for which two coincident pulses are produced are accepted only when a K-alpha or K-beta etc. fluorescence photon (30 keV) is detected within the sensitive volume. The location of photons will be performed through the delay line concept, to an accuracy of the order of 1 mm. Collimation, together with the active veto system of the detector, reduces the background further.
The mask is a URA twin prime with a basic pattern of 71X73 pixels. It will repeated partly with 18 pixels on each side. A collimator, with cells sizes equal to that of a mask pixel, ensures an optimum imaging environment of this coded aperture camera.
| Detector type | Multi-Wire Proportional Counter |
| Detector gas | Xe |
| Detector gas pressure at | 5 atm |
| Active detector area | 1744 cm**2 |
| Distance Aperture-Detector | 2300 mm |
| Field of View | 4.6 X 4.9 (FCFOV), ~6 X 6 (PCFOV) |
| Mask size | 73 X 71 elements (basic, 105 X 105 total) |
| Mask element size | 5.8 X 5.8 mm2 |
| Mask open fraction | 0.5 |
| Angular Resolution (FWHM), on-axis | 8.7 arcmin (40 arcsec SLA for a 5sigma) |
| Active photon energy range | 5-150 keV |
| Photon energy resolution | <= 5% |
| Sensitivity typical | ~mCrab in one day |
Taken from the Coded Aperture Imaging in High Energy Astrophysics pages
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