Chiara and Jenne.

Work permit 8410

Experiment proposal on DCC T1900656

As a first step of the experiment, we prepared the front end models to send a cps signal from HAM2 to HAM3 to set an additive offset. This will help to reduce the differential motion between the two chambers and to improve IMCL and PRCL signals.

To do it, we had to modify the ISI HAM2 model which has a library part in the common directory, used also by the other HAMs. We took CPS_X just before it is summed with gs13 and sent it to the top level of the  model. Then we used a SHMEM bridge to send it to HAM3, connecting it to the SUS_OFFLOAD_X.  Adding another output to the library part means that it is also present in the othe HAM models. So this output has been connected to ground for HAM3, HAM4, HAM5 and HAM6.

Since the library part is in the common directory, we also checked that it is not used by LLO.

We compiled all the HAM models and check that there are no errors; we did not do the install or reboot. We checked all our changes into the svn.

In coordination with people working on alignment, we are going to test the new models during next week.