1 / 11

Supervisors : Petra Riedler and Vito Manzari

OPERATING CONDITIONS OF ALICE SILICON PIXEL DETECTOR. CHARLES Gabriel. Supervisors : Petra Riedler and Vito Manzari Many thanks to : Michele Morel, Michele Caselle, Andre Augustinus, Cesar Torcato De Matos. Outline. Operating conditions of ALICE SPD. 1/8. Dew point in the ALICE cavern.

jaeger
Download Presentation

Supervisors : Petra Riedler and Vito Manzari

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. OPERATING CONDITIONS OF ALICE SILICON PIXEL DETECTOR CHARLES Gabriel Supervisors : Petra Riedler and Vito Manzari Many thanks to : Michele Morel, Michele Caselle, Andre Augustinus, Cesar Torcato De Matos

  2. Outline Operating conditions of ALICE SPD 1/8 Dew point in the ALICE cavern Humidity effect on half-staves Half-staves in ALICE Measurements in laboratory (1)

  3. 1) Dew point What is the dew point ? 2/8 The relative humidity (RH) is defined as the ratio of the partial pressure of water vapor compared to the saturated vapor pressure of water vapor at a given temperature. The dew point is the temperature at which the partial pressure of water vapor in the air is equal to its pressure of saturated vapor. (2) Example : at ambient temperature 20°C and a relative humidity of 60% the dew point is 12.01°C. Summer Student perception Too dry (one drink is needed, at least) Perfect (drink is not necessary, but it is the perfect weather for a drink at resto 1) Uncomfortable (best case : drink is compulsory) Dewpoint (°C) 10 28

  4. 1) Dew point ALICE and the Dew point 3/8 Difference between ambient temperature and dewpoint decreases from 12°C to 7°C The difference decreases since March How can it be explained ? Cavern dew point follows the outside trend But… it is just in average (3)

  5. 1) Dew point ALICE and the Dew point 4/8 The difference can sometimes be as low as about 4°C. Conclusion : investigate the humidity effects will explain the present and futur consequences of these operating conditions on the detector.

  6. 2) Humidity effects How is the heart of ALICE ? 5/8 a. In ALICE I(V) curves 6 curves for each sector of one side. 10 sectors, 2 sides so 120 curves. No general trend and no important change

  7. 2) Humidity effects Lab-tests ? 6/8 b. Lab-tests HS_143 bus pad HS_143 pixel pad

  8. 2) Humidity effects Conclusion 7/8 There is no major change in the behavior of the detector since the breakdown of the LHC. The operating conditions have not affected the SPD. But for this kind of problem only long term study makes sense. There is not yet any change in the behavior of the tested half-stave in the laboratory. Maybe we see the begining of some trend. So now we have to continue the lab-test, wait for some change, or not and check if the same behavior is seen in the ALICE SPD.

  9. 1) Dew point References 8/8 (1) The ALICE experiment at the CERN LH. The ALICE Collaboration, K Aamodt et al 2008 JINST 3 S08002 (2) Barenbrug, A.W.T., Psychometry and Psychometric Charts, 3rd Edition, Cape Town, S.A. : Cape and Transvaal Printers Ltd., 1974 (3) Website for the Geneva temperatures : http://www.wunderground.com (4) M. Balkanski and R.F. Wallis, Semiconductor Physics and Applications, Oxford University Press, reprinted 2007. FOR LISTENING

  10. 2) Humidity effects The heart of the heart of ALICE 9/8 SSD SDD SPD Lout=97.6 cm Rout=43.6 cm

  11. 2) Humidity effects Dew point 10/8

More Related