Electronics for AYEball
This list of things to remember about the electronics is by no means complete, but is at least a guide so things are not forgotten.
At the beginning of a run:
- Check the RF-gg overlap #1. It is in the top of the LeCroy quad coincidence box in the Ge electronics rack. Trigger the scope with the gg signal. The RF should be ~2/3 of the way towards the end of the gg signal. The delay to adjust for this purpose is the top half of the Phillips delay box. The bottom half should never be touched. The last word on setting the correct delay should be looking at what channel the germanium TDC peaks appear in. Pick a place and make sure it stays there for the entire run.
- Adjust the g and gg delay at the back of the FMA. These are the 1st and 3rd elements, respectively, of the Phillips gate generator in the first slot of one of the bins at the back. The g and gg signals should be delayed so they line up with the PPAC signal. This makes all triggers arrive at the master fan-in at the same time.
- Adjust the implant and decay trigger delays at the back of the FMA for the same reason as above. They are in the DSSD rack in a LeCroy GDG.
- Check the PPAC TDC fast clear coincidence overlap at the back of the FMA.
- Check the Ge TDC fast clear and Ge ADC gate VETO at the front of the FMA.
- Adjust all the prescale factors to something reasonable. The PPAC and gamma singles events will be unplugged for the DSSD runs so the factors don't matter for these two trigger types.
- Check the monitor gain.
- Check the PPAC DE gain.
- Choose appropriate ion chamber pressure (if you are using it).
- Check the ion chamber anode signal gains.
- Make sure the out-of-lock signal is plugged in before real data collection begins. It comes from the data room on a patch panel just below the Ge logic at the front of the FMA.
- Enter the proper BETA value for DAPHNE (FIX BETA number).
- Unplug out-of-lock signal at front of FMA.
- Plug in the PPAC and gamma singles triggers if you want to set them up.
- Set prescale factors to appropriate value, probably 1.
Changing beam energy:
- Check the RF-gg overlap and adjust RF delay #1.
- If it is a significant change in recoil velocity adjust the g and gg delays at the back of the FMA.
- Enter the new BETA value for DAPHNE.
- Is ion chamber pressure still OK (if you are using it)?
Last Updated: October 13, 1995 (D.J. Blumenthal, email@example.com)