| 1. |
|
|
| 2. |
- Mahout, G., et al.
(författare)
-
Irradiation studies of multimode optical fibres for use in ATLAS front-end links
- 2000
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 446:3, s. 426-434
-
Tidskriftsartikel (refereegranskat)abstract
- The radiation tolerance of three multimode optical fibres has been investigated to establish their suitability for the use in the front-end data links of the ATLAS experiment. Both gamma and neutron irradiation studies are reported. A step-index fibre with a pure silica core showed an induced attenuation of similar to 0.05 dB/m at 330 kGy(Si) and 1 x 10(15) n(1 MeV Si)/cm(2) and is suitable for use with the inner detector links which operate at 40-80 Mb/s. A graded-index fibre with a predominantly germanium-doped core exhibits an induced attenuation of similar to 0.1 dB/m at 800 Gy(Si) and 2 x 10(13) n(1 MeV Si)/cm(2) and is suitable for the calorimeter links which operate at 1.6 Gb/s. Measurements of the dose rate dependence of the induced attenuation indicate that the attenuation in ATLAS will be lower.
|
|
| 3. |
- Andrieux, M. L., et al.
(författare)
-
Single-event upset studies of a high-speed digital optical data link
- 2001
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 456:3, s. 342-351
-
Tidskriftsartikel (refereegranskat)abstract
- The results from a series of neutron and photon irradiation tests of a high-speed digital optical data link based on a commercial serialiser and a vertical cavity surface emitting laser are described. The link was developed as a candidate for the front-end readout of the ATLAS electromagnetic calorimeter. The components at the emitting end of the link were unaffected by neutron and photon irradiation levels exceeding those expected during 10 years of LHC running. However, the link suffered from Single-Event Upsets (SEUs) when irradiated with energetic neutrons. A very general method based on the Burst Generation Rate (BGR) model has been developed and is used to extrapolate the error rate observed during tests to that expected at the LHC. A model-independent extrapolation was used to check the BGR approach and the results were consistent once systematic errors were taken into account.
|
|
| 4. |
- Bongi, M, et al.
(författare)
-
PAMELA : A satellite experiment for antiparticles measurement in cosmic rays
- 2004
-
Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 51:3, s. 854-859
-
Tidskriftsartikel (refereegranskat)abstract
- PAMELA is a satellite-borne experiment that will study the antiproton and positron fluxes in cosmic rays in a wide range of energy (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and with high statistics, and that will measure the antihelium/helium ratio with a sensitivity of the order of 10(-8). The detector will fly on-board a polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3-year-long mission. Particle identification and energy measurements are performed in the PAMELA apparatus using the following subdetectors: a magnetic spectrometer made up of a permanent magnet equipped with double-sided microstrip silicon detectors, an electromagnetic imaging calorimeter composed of layers of tungsten absorber and silicon detectors planes, a transition radiation detector made of straw tubes interleaved with carbon fiber radiators, a plastic scintillator time-of-flight and trigger system, a set of anticounter plastic scintillator detectors, and a neutron detector. The features of the detectors and the main results obtained in beam test sessions are presented.
|
|
| 5. |
- Adriani, O., et al.
(författare)
-
The PAMELA experiment on satellite and its capability in cosmic rays measurements
- 2002
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 478:02-jan, s. 114-118
-
Tidskriftsartikel (refereegranskat)abstract
- The PAMELA equipment will be assembled in 2001 and installed on board the Russian satellite Resurs. PAMELA is conceived mainly to study the antiproton and positron fluxes in cosmic rays up to high energy (190 GeV for (p) over bar and 270 GeV for e(+)) and to search antinuclei, up to 30 GeV/n, with a sensitivity of 10(-7) in the He/He ratio. The PAMELA telescope consists of. a magnetic spectrometer made up of a permanent magnet system equipped with double sided microstrip silicon detectors a transition radiation detector made up of active layers of proportional straw tubes interleaved with carbon fibre radiators; and a silicon-tungsten imaging calorimeter made up of layers of tungsten absorbers and silicon detector planes. A time-of-flight system and anti-coincidence counters complete the PAMELA equipment. In the past years, tests have been done on each subdetector of PAMELA; the main results are presented and their implications on the anti-particles identification capability in cosmic rays are discussed here.
|
|
| 6. |
|
|
| 7. |
- Bergenius, S., et al.
(författare)
-
Proton irradiation response of CsI(Tl) crystals for the GLAST calorimeter
- 2003
-
Ingår i: 2003 IEEE Nuclear Science Symposium Conference Record. - : IEEE Press. - 0780382579 ; , s. 1096-1099
-
Konferensbidrag (refereegranskat)abstract
- The electromagnetic calorimeter of the Gamma-Ray Large Area Space Telescope (GLAST) consists of 16 towers of CsI(Tl) crystals. Each tower contains 8 layers of crystals (each 326.0x26.7x19.9 mm3) arranged in a hodoscopic fashion. The crystals are read out at both ends with photodiodes. Crystals produced by Amcrys-H (Ukraine) are used. A full size crystal was irradiated with a 180 MeV proton beam and the radiation induced attenuation was measured. The induced radioactivity of the crystal was also studied. In this paper we will discuss the damage due to proton irradiation and compare this with the expected in-orbit background flux.
|
|
| 8. |
- Bergenius, S., et al.
(författare)
-
Radiation hardness tests of CSI(Tl) crystals for the GLAST electromagnetic calorimeter
- 2003
-
Ingår i: Proceedings of 28th International Cosmic Ray Conference. ; , s. 2787-2790
-
Konferensbidrag (refereegranskat)abstract
- The electromagnetic calorimeter of the Gamma ray Large Area Space Telescope(GLAST) consists of 16 towers of CsI(Tl) crystals. Each tower contains 8layers of crystals (each 326.0×26.7×19.9 mm3) arranged in a hodoscopic fashion.The crystals are read out at both ends with PIN photodiodes. Crystals producedby Amcrys-H (Ukraine) are used. As a part of the quality control procedureduring crystal production, samples from the uncut boules are systematically irradiatedwith gamma rays from a 60Co source. Studies have also been carried outto verify the correspondence between the post-irradiation properties of the boulesamples and the full size crystals which are subsequently cut from the boule. Thefull size crystals have also been irradiated with a 180 MeV proton beam and theradiation induced attenuation measured.
|
|
| 9. |
- Charlton, D. G., et al.
(författare)
-
System tests of radiation hard optical links for the ATLAS semiconductor tracker
- 2000
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 443:03-feb, s. 430-446
-
Tidskriftsartikel (refereegranskat)abstract
- A prototype optical data and Timing Trigger and Control transmission system based on LEDs and PIN-diodes has been constructed. The system would be suitable in terms of radiation hardness and radiation length for use in the ATLAS SemiConductor Tracker. Bit error rate measurements were performed for the data links and for the links distributing the Timing, Trigger and Control data from the counting room to the front-end modules. The effects of cross-talk between the emitters and receivers were investigated. The advantages of using Vertical Cavity Surface Emitting Lasers (VCSELs) instead of LEDs are discussed.
|
|
| 10. |
- Larsson, S., et al.
(författare)
-
The Background of the INTEGRAL SPI Anticoincidence Shield and the Observations of GRBs
- 2004
-
Ingår i: PROCEEDINGS OF THE 5TH INTEGRAL WORKSHOP ON THE INTEGRAL UNIVERSE. - : European Space Agency. - 9290928638 ; , s. 649-652
-
Konferensbidrag (refereegranskat)abstract
- The anti-coincidence shield, ACS, of the spectrometer, SPI (Vedrenne et al., 2003), on INTEGRAL provides the possibility to study temporal properties of gamma-ray bursts (GRBs) with high resolution (Rau et al. 2004). To correctly interpret the results of the analysis, a good understanding of the back,ground and noise levels of the instrument is required. The back-round noise of the ACS, oil timescales up to the length of a GRB, has a Gaussian distribution and its power is independent of frequency, that is, it is white noise. However, it does not follow a Poisson statistic since on average the variance is similar to 1.6 times larger than the mean, and varies significantly. We find a systematic relation between the mean count rate and its variance. The ratio, variance/mean, decreases as the mean count rate increases. As well as helping to understand the cause of this effect, this characterisation is useful when modelling the time variability of GRBs. To illustrate the discussion we present some GRB light curves detected by the SPI/ACS and shortly discuss the analysis that has been made of them.
|
|
