PC STATUS – meeting 18/12/2015

PHASE CAMERA INSTALLATION PLANNING

Phase Camera 1 (PC1): we refer to the Phase Camera installed on the EIB as to the PC1.

The setup has been installed in October (see log-entry 32745). The first amplitude and phase image have been taken at the end of November. Nonetheless, these data have to be shared on the logbook, and new data are necessary to test the setup. Moreover, before starting a new measurement session, it is necessary to check once more the PC1 telescope design.

In order not to overlap with the Commissioning activity, it is preferable to plan well in advance the Phase Camera measurements. During the data taking, it is important to check whether the beam scanned by the scanning mirror gets reflected back and introduces noise which disturbs the lock of the Mode Cleaner or of the Reference Cavity. If this is the case, it is necessary to think about a solution to avoid the back-reflection of the beam.

Another issue concerning the design is related to the possibility of scanning only the Test beam instead of Scanning both of them, as Bas Swinkels suggests, since it would maximize the SNR. It would be preferable to have a clear comparison between the two cases, listing the pros and cons of both. Possibly, if there is enough time, the two possible configurations can also be tested for PC1.

Phase Camera 2 (PC2): we refer to the Phase Camera to be installed on the SPRB  as to the PC2.

The telescope design has been mostly finalized. The installation of PC2 is subject to the presence of the B4 beam on SPRB, but it is fair enough that it will be available by the end of January. If this is the case, a coordination is needed to schedule the PC2 installation avoiding overlaps with other group’s work.

Phase Camera 3 (PC3): we refer to the Phase Camera to be installed on the EDB  as to the PC3.

The telescope design is still missing, but all of the information about the optics along the beam path have been asked to Romain Bonnand, who is going to provide them as soon. Also for this case, the installation is related to the presence of the beam and has to be agreed with the other group’s work.

ELECTRONIC ISSUES

For all of the Phase Cameras, it is necessary to have a feedback from LAPP in order to finalize the TOLM interface.

Moreover, the linearity of the PD response at the edges has to be checked.

SIMULATIONS

In order to better understand what kind of signals should we expect from the phase camera, it is good to start an intensive session of simulations. This can be done with the help of Jerome Degallaix.

POSSIBLE PLAN

One possible plan is to schedule the new measurements for PC1 for the week starting from Jan 25^th. By that time, if the B4 beam is present, the PC2 can also be installed. In the meanwhile, FFT simulations can be carried on to get a better idea about the signals that we should expect from the PC.

Moreover, a clear commissioning plan has to be done in order to coordinate also with people on the site.