On detector electronics: High voltage part Tilecal session in ATLAS upgrade week (Tuesday 10 November 2009) François Vazeille  What are the constraints for the Dividers and the HV regulation? the Dividers and the HV regulation?  Proposed R&D scheme  Status at Clermont-Ferrand 1

What are the constraints for the Dividers and the HV regulation? 2  HV Dividers (see the specifications in my previous talks) - To fit the space inside the PMT Blocks, as interface in between the PMT and the 3in1 card without any cable. - To keep the PMT linearity in the extreme sLHC luminosity, within 1%.  HV regulation (see the specifications in my previous talks) - To reach at least the 0.5 V rms regulation stability, as specified by Tilecal. - To be better by reaching the present ATLAS performances at least 10 times better. - To improve the present reliability and to bring new facilities (Individual switching, access…) knowing that the radiations will be bigger by about a factor 10 in the pit.  In any case, the cost and the funding will drive the final solution.

Proposed R&D scheme 3 DIVIDERS  New design using transistors in the last stages.  Comparison tests of old/new designs using the PMT Test Bench, by putting DC currents simulating the MB induced events at sLHC.  Choice of active components with respect to the expected radiation, and radiation tests of new Dividers.  Rebuilding of the Divider Test Bench.  Final scheme fitting the final 3in1 new design Depending from the 3in1 schedule 0.5 FTE (0.25 Ie, 0.15 Tm, 0.1 on-line) 0.6 FTE (0.3 Ie, 0.1 Tm, 0.2 on-line) Man power not yet estimated but not big.

4 HV REGULATION - 6 solutions + ASIC Options * - Manpower if chosen On DrawersUSA15 Option 0: Full re-use - Aging: at least 15 years old in Radiations? True radiation level waited. - Compatibility with new Drawers. - No R&D manpower, except maintenance. Option 3: Re-use of present cards - Aging: at least 15 years old in Integration in USA Racks: space? - Long cables for services + Drawer Bus. - R&D manpower : 2.0 FTE (0.5Ie, 0.5Te, 0.5Tm on-line) Option 1*: New design with COTs - New radiation tests. - New design. - R&D manpower: 4.0 FTE (2Ie, 1Te Test Benches on-line) Option 4*: New design - Conception and integration in USA15, including HV source (commercial?). - Long cables for services + Drawer Bus. - R&D manpower : 3.5 FTE (1.5Ie, 0.5Te, 0.5Tm, Test Benches on-line) Option 2*: New design with radhard components … COST! - Radiation tests to validate. - New design - R&D manpower : 4.0 FTE (2Ie, 1Te Test Benches on-line) Option 5: Commercial solution (CAEN?) … COST! - Integration and long cables for services + Drawer Bus. - R&D manpower : 1.5 FTE (0.5Ie and Te, 0.5Tm on-line)

In 2010: - Comparison of the 6 (or 9) solutions, including the costs. R&D manpower: 1 Ie. - Propositions and final choice, knowing that the funding will play an important role.  Schedule: In : Final design, with new Test Benches and other tests  See the previous table for the requested manpower. 5

Status at Clermont-Ferrand 6 DIVIDERS New design - Made (Michel Crouau). - Order of components for 20 Dividers.  Delivery end January Lab tests on some Dividers  First validation.  Design and validation of new Divider Test Bench (Not before February). - Systematic tests on the new Divider Test Bench, then on the PMT Test Bench. using 20 PMT/Divider sets, before July. Divider Test bench (from the previous Test Bench) - Mechanics: OK (Pierre Verdier). - Electronics and commands: OK  new Labview version (Roméo Bonnefoy), except new test about DC current injection in transistors: in progress. - On-line: in progress, Roméo then Patrick Lafarguette. Radiation tests to organize and to prepare in 2010, with an active Test Bench during the radiation exposure. At this moment: fits the foreseen schedule, with manpower in and funding in 2009 (10 K€).

HV REGULATION  The Clermont-Fd team is officially authorized (by LPC management) to work on the comparison in 2010, and to make preliminary tests when requested. - Manpower as requested : 1 Engineer in electronics. - Table of options: first studies in 2009 by Robert Chadelas, including the first cost estimates (From 0.5 M€ to more than 3 M€). - Activity going on in 2010, including special tests (Regulation loop, long cables and noise…).  Once the final option will be chosen by Tilecal  New request for manpower to LPC management. 7