Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 Status chamber testing/database Chamber testing procedures finalized may 13 –See manual.

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Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 Status chamber testing/database Chamber testing procedures finalized may 13 –See manual Vers. 5 in forum.gsi.de/Alice/TRD chamber tests Use of 109 Cd source in testing Database

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 55 Fe source 55 Fe EC to 55 Mn, K = 5.9, 6.5 keV T.Lehmann, 2003 Transmission radiator at 5.9 keV is about 1%

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 55 Fe source for gain uniformity N0 = photon flux from the source A = absorption in radiator A = variation in absorption (radiator thickness,glue,..) Ns = number of photons into gas volume Ns = N0 x (1-A) Ns) = dNs dN0. (N0) + dNs dA. (A) (Ns) Ns N0 ~ Ns. (A) (Ns) Ns ~(A/1-A) (A) A for A ~ 0.99: (A/1-A) ~ 100 for A ~ 0.5: (A/1-A) ~ 1

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 absorption radiator Absorption measured as function of energy T. Lehmann, 2003 transmission > 50 %: -> E(photon) > 10 keV Source parameters: 1)photon energy 2)life time 3)no neutrons -> 109 Cd

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 109 Cd source (453 d) 109 Cd EC to 109 Ag, K = 22.9, 26.0 keV K K Ag*(7/2 +), E=88 keV Collimator: Absorption (1mm Pb) at 88 keV ~ 90 %

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 109 Cd spectrum 109 Cd spectrum measured with TRD chamber 2 nd peak at approx. 8 keV -> compatible with E(K of Z~29 (copper) Confirmation by AEA: Casing material monel ( 1/3 copper, 2/3 nickel) Information by AEA: Casing material could be Titanium, (Z=22), E(K ~ 4.5 keV), Cd contains Silikat (Na-Al)

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 1d scan X-ray vs 109 Cd source L1C1#020 measured with X-ray tube, Cd source X-ray scan Cd scan

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 2d scan X-ray vs 109 Cd source L1C1#020 measured with X-ray tube, Cd source X-ray scan Cd scan

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 Conclusions 109 Cd source can be used for measuring –Gain uniformity –Absolute Gain –Gain stability Absolute gain measurement has to be done with care with present Cd source (intensity 2 nd peak might be collimation dependent) -> Cd source with Titanium casing

Rainer Schicker, Univ. Heidelberg Cheile Gradistei, sept 26, 2005 Status database Sascha Freuen has graduated and left sep 15 Stefan Zimmer has started as HiWi and taken over the database, no other involvement in TRD activities As of sep 22, writing of some leak rate parameters to database successful

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