CDC Preamps
Preamp4 (GlueXdoc1364 Tbl 2 Row 2)
This section (blue background) contains links to data obtained when our gas mixer was not operating reliably.
On June 23, we came to the conclusion that our old preamplifier bit the dust. Detailed pictures showing how its performance has changed over the last several months are below. These clearly show that the gain increased by a factor of at least four and that there is substantially more noise. This later turned out to be confusion caused by a faulty mix of gas.
The following link points to comparisons of cosmic data taken with the old preamplifier several months ago and with the new preamplifier. They clearly show that the signals (for the same gas and voltage settings) are larger with the new preamplifier.
The following plots are taken using the new preamplifier with our FADC range decreased to match
the lower maximum output voltage from the new preamplifier (about 500mV). The old preamplifier
had a higher limit (~1V).
Based on the fact that our old preamplifier died, the following plots should not be used to make comparisons between the old and new preamplifier.
- Preamp 4 : Comparison of 'scope traces with earlier preamps
- Preamp 4: Comparison of 55Fe data with original preamp
- Preamp 4: Comparison of 55Fe data with original preamp at lower voltage
- Preamp 4: 55Fe 'scope traces at lower voltage
(end of dodgy gas section)
