AURIGA: the SQUID for run2
Before acquiring the signal developed by the transducer it is necessary to
amplify it: ideally this should be done without introducing further noise.
In reality a noisless amplifier does not exist and we are therefore forced
to use a noisy amplifier that we choose to be the less noisy
The amplifier for AURIGA is based on a SQUID (Superconducting QUantum Interference Device), as in the first run RUN1. The R&D program that AURIGA carried out in the past years, and which is still in progress, has allowed a detailed comprehension of the SQUID properties and consequently has led to the developement of a very quite amplifier, which we emply in the second run RUN2.
For the second run AURIGA will employ a two-stage SQUID amplifier. This is