On detector electronics: High voltage part

1. 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? • Proposed R&D scheme • Status at Clermont-Ferrand 1

2. What are the constraints for the Dividers and the HV regulation?  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. 2

3. Proposed R&D scheme DIVIDERS  New design using transistors in the last stages. 2009 0.5 FTE (0.25 Ie, 0.15 Tm, 0.1 on-line) • Comparison tests of old/new designs using the PMT Test Bench, by putting DC currents simulating the MB induced events at sLHC.  Rebuilding of the Divider Test Bench. 2010  Choice of active components with respect to the expected radiation, and radiation tests of new Dividers. 0.6 FTE (0.3 Ie, 0.1 Tm, 0.2 on-line) Depending from the 3in1 schedule  Final scheme fitting the final 3in1 new design. Man power not yet estimated but not big. 3

4. HV REGULATION • 6 solutions + ASIC Options * • -Manpower if chosen 4

5.  Schedule: • • 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. • In 2011-2012: Final design, with new Test Benches and other tests  See the previous table for the requested manpower. 5

6. Status at Clermont-Ferrand DIVIDERS At this moment: fits the foreseen schedule, with manpower in 2009-10 and funding in 2009 (10 K€). • New design - Made (Michel Crouau). - Order of components for 20 Dividers.  Delivery end January 2010. - 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. 6

7. 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