Multipoint PCA

The PCA has been modified in a backwards-compatible way to accomodate the shadows cast by the NCDs on the PMTs. For PCAs during the NCD phase multiple laserball positions are used so that all of the PMTs are sufficiently illuminated. Up to five laserball positions can be used, though two positions has been found to be sufficient.

Three main additions were made to the PCA:

MPLP Titles Bank

The Multipoint Pca Laserball Position bank stores the ideal laserball positions and the tolerances for deviation of the actual laserball positions from those ideals. The PMT mask and information about the runs used to create it are also stored in this bank.

PMT Mask

The mask is used to determine which PMTs are calibrated from which laserball positions. The mask is optional. It is off (i.e. all PMTs calibrated by all laserball positions) by default, and can be turned on via the TPCA1 bank.

Time-of-Flight Correction

When using multiple laserball positions it is necessary to adjust the timing of the PMT signals so that all of the PMTs are calibrated consistently. The ToF correction is off by default for backwards compatibility, and can be turned on via the TPCA1 bank.