ASIC meeting June 2x, 2010

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.

• CDC_old_preamp_then_and_now

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.

• Preamp 4: Comparison of cosmic data with original preamp

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).

• Preamp 4: Quick look at cosmic data with reduced fADC range