Difference between revisions of "MiniDC Signals 10-0-07"
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| − | Signals were observed in the LDS on the Mini DC prototype | + | Signals were observed in the LDS on the Mini DC prototype sense wires capacitively coupled to a digital oscilloscope. The drift chamber was filled with a Ar/CO2 (75/25) gas mixture. |
The apparatus | The apparatus | ||
Revision as of 01:48, 10 October 2007
Signals were observed in the LDS on the Mini DC prototype sense wires capacitively coupled to a digital oscilloscope. The drift chamber was filled with a Ar/CO2 (75/25) gas mixture.
The apparatus
The following Voltages were established on the Drift chamber wires
| HV settings | |
| Wire | Volts |
| Sense | 1800 |
| Field | -750 |
| Guard | 750 |
The Scintillator mounted on top of the Chamber was set to -900 Volts
Below is a scope picture representing the observation of a coincidence event between a particle which passed through both the top scintillator and the Mini Drift Chamber. The scope was triggered on the scintillator output. The top trace is the output of the drift chamber from one of the sense wires capacitively coupled to the scope and terminated in 1 Meg Ohm. The bottom trace is the fast output from the Scintilaltor.
Noise Level Measured by scope in infinite persistance mode indicate that the Mini Prototype with plastic feedthroughs (Plastica) has noise levels spanning +/- 10 mV. A PMT connected to a scintillator shows noise levels around+/- 2.5 mV.
A few Characteristic scope pictures of event triggered on the chamber output. The trigger threshold was set to ~-14 mV for all but the last picture which was set at -17 mV. Signals beyond -14 mV are well outside the intrinsic detector noise and considered ionization events.
