GSI Helmholtzzentrum für Schwerionenforschung
Dear All As an example, the results of testing chamber l2C0#3 are shown below (leakrate, gain curve, gain uniformity) 1.Leakrate ========== The oxygen content within the chamber is measured in intervals of 5 minutes. The asymptotic value is an indicator of the leakrate. The flow rate was set at 10 l/h which leads to a time constant of ~4h Fit : f(x)=a+b*exp(-c*x) 2.Gain Curve ============ The anode voltage is increased in steps of 20 V starting at 1000 V up to 1600 V. At each step the anode current is recorded. Fit : f(x)=a+b*exp(c*x) 3.Gain Uniformity ================= There are two different measurement modes: 1. 1D scans with 4mm steps .Here you can clearly see the radiator bars, which absorb very strongly 1.1 4mm steps scan in z-direction at two different phi positions 1.2 4mm steps scan in phi-direction at two different z positions 2. A full 2D scan with 4cm equidistant steps. Here one can only see the radiator bar in the middle very clearly, due to the bigger step size.
Dear Sascha, very impressive pictures indeed. Just on question: in all cases the X-ray tube was used for irradiation? Regards, Harry
Dear Harry For the gain curve measurement the Sr90 source was used. Regards Sascha