ECAL status and plans C-side A-side Further plans People involved: Alexander Arefiev, Boris Bobchenko, Yury Gilitskiy, Tengiz Kvaratskheliya, Irina Machikhiliyan, Olga Zhiryakova Special thanks to Iouri Guz for support

MESSAGE TO GLOBAL COMMISSIONERS on behalf of ECAL group DURING YOUR TESTS DO NOT TOUCH ECAL CABLING! CALL US AND CONSULT FIRST! IF YOU THINK YOU BURNED SOMETHING – DO NOT KEEP IT SECRET. SHARE IT WITH US. MONDAY SITUATION: SOMEBODY DISCONNECTED SOME POWER LINES FROM BOX #7. ECAL GROUP WAS NOT INFORMED, NO ENTRY INTO LOGBOOK.

PMTs / LEDs / interconnecting cabling are checked; malfunctions/mistakes found are (mostly) fixed PMTs / LEDs / interconnecting cabling are checked; malfunctions/mistakes found are not yet fixed PMTs / LEDs / interconnecting cabling are not yet checked (mostly due to missing parts of necessary hardware) ECAL commissioning: status (I)

ECAL commissioning: status (II), C-side  1 week access (end of October);  Post-access situation: 99.7% of PM channels / 100% of LED channels are operational; connections mapping (PM/LED control part) is updated in DB; integrators for PM current measurement are installed on the wall. minor optimization of voltage delivery/control boxes to stabilize output voltage - is done for 3 boxes (test batch to see unexpected behaviour if any);  Pending tasks:  integrators: fine adjustment (access to the wall is needed);  integrators readout: install additional voltage delivery/control box under ECAL platform;  PIN-diodes: check system serviceability and complete fine gain tuning to account for large PM gains spread over ECAL (access is not needed);  Hardware missing:  2 FEBs to readout PIN output signals;

ECAL commissioning: status (III), A-side  Wall became accessible week ago;  Current situation: 86% of PM channels / 89% of LED channels are checked;  problematic channels are under study / connections mapping in DB is under correction; integrators for PM current measurement are installed on the wall. To readout them additional voltage delivery/control box is installed under ECAL platform; missing voltage delivery/control boxes are installed; minor optimization of voltage delivery/control boxes to stabilize output voltage - is done for 4 boxes (test batch to see unexpected behaviour if any);  Pending tasks:  PM/LEDs (R/O crate #21): finish quick check of PM/LED channels serviceability;  PIN-diodes: check system serviceability and complete fine gain tuning to account for large PM gains spread over ECAL (access is not needed);  integrators: fine adjustment (access to the wall is needed);  Hardware missing:  One R/O crate (#21) is not equipped with MARATON power supply;  6 FEBs to readout PM output signals;  R/O crate 15 has defective slot, therefore one LED TSB unit can not be installed;

ECAL commissioning: further steps:  This week: repair of A-side  Further steps:  finish quick check of PM/LED channels serviceability for R/O crate 21;  check PIN-diodes system;  when global tests will be finished: check again C-side; start to measure PM regulation curves (DAQ is required);  optimize the rest of voltage delivery/control boxes (if no unexpected behaviour will be observed in test batch);  Access request: January 2008, both C and A-sides;

Measurement of the relative time spread in the cabling of Monitoring System on behalf of Ilya Kudryashov (MSU) in the context of the preparation to ECAL time alignment  LED fire / PIN signal cable lengths are measured (reflections method) and tabulated;  Selected results for lengths spread:  LED fire cables:  r. m. s. < 0.1m  max spread < 0.6m  PIN signal cables:  r. m. s. < 0.17m  max < 0.6m  Major source of systematics : time precision of generator fronts reproduction (dominated by temperature dependence); found to be 0.7 ns / cable length