Active Dividers Tilecal upgrade meeting at Valencia (19-21 November - - PowerPoint PPT Presentation

Active Dividers

Tilecal upgrade meeting at Valencia (19-21 November 2014)

François Vazeille

• n behalf of Roméo Bonnefoy, Michel Crouau (Now retired), Dominique Pallin, Christian Fayard,

Marie-Lise Mercier, Eric Sahuc, Timothée Theveneaux-Pelzer

 PMT issues  Concept of active Dividers  Systematic tests of passive/active dividers  Radiation tests  Conclusion

1

• PMT issues

PH A D1 … D8 High Lumi. Effect on PMT entrance: Gain ↓ instantaneous L ,↑ integrated L, already seen from Tiles close to the Beams*. Effects on the last Dynodes: Gain ↑ at HL-LHC. PMT signal



Minimum Bias Events at HL-LHC  High DC current on the last dynodes ( Amplification at each stage)  Decrease of the interdynode voltages  Increase of voltages on the first dynodes because HV kept constant  Increase of PMT: non-linearity of AC pulses for high DC currents. *2 PMTs back to LPC:  PMT Test Bench could provide useful information.

2

• Concept of active Dividers

Passive Dividers Active Dividers ▪ High sensitivity to high DC current  Non linearity to AC PMT pulses ▪ Transistors on the last 3 stages  Constant voltages. ▪ Diodes on the 3 last stages  Protect transistors/Off-On switching.

3

• Systematic tests of passive/active Dividers

No other electronics than a scope (No bias)

Active Passive

 Comparisons for a given AC pulse (~ 100 GeV)

• f 20 sets ″PMT-passive-active Dividers″

as a function of DC (Minimum Bias).

▪ Without PMTs: on the Divider Test Bench ▪ With PMTs: on a dedicated set-up

4

 Comparisons of sets of 10 passive/active Dividers.

 Full concept validation with the goal of NL < 1%

Atlas Note Active Dividers for the Tile Calorimeter for the ATLAS Detector ATL-TILECAL-INT-2014-005 (02 July 2014) [Clermont-Ferrand authors] 27 pages Passive Active 10 µA 3.4 ± 0.6 50 µA < 0.5 40 µA 13.5 ± 2.4 120 µA < 1 Non-linearity in % versus DC (Averages over 20 bases)

• Passive Dividers are no longer fitting the specifications.
• Active Dividers fit perfectly with a large safety margin.
• Not shown today: good agreement with simulations.

DC max Tiles  10 µA Cracks  40 µA at HL-LHC

5

• Radiation tests

▪ Test Bench + PCB + Analysis: Clermont-Ferrand

with a current injection of 40 µA on dynode 8 (to push the NL).

Irradiated PCB 20 Dividers (Atlas rules) and also 8 Diodes and 16 Transistors

▪ ATLAS rules on location, simulations, new Safety factors

NIEL: 0.6 1013 eq-1 MeV n/cm2 (pushed up to 1.5 1013 old Safety factors) TID : 225 Gy (pushed up to 525 with old Safety factors)

▪ Irradiations

Neutrons: Valduc (CEA France) by Clermont-Fd team. Gammas: Brookhaven (USA) by Argonne team.

6

Full certification at the official doses and also at the upper doses.  5 criteria on Dividers and also Diodes and Transistors

Atlas Note "NIEL and TID certifications of the active Dividers of the Tile Calorimeter of the ATLAS detector for the Phase II upgrade ATL-COM-TILECAL-2014-074 (Submitted) [Argonne + Clermont-Ferrand authors] 44 pages

• R&D completed with success.
• Production/Certification of 350 active Dividers for ATLAS 2015

(Cracks et MBTS).

• Test Bench refurbished for both passive/active Dividers

ready for future productions.

• ATLAS decision to come about a partial/total replacement

for the upgrade.

7

Full certification at the official doses and also at the upper doses.  5 criteria on Dividers and also Diodes and Transistors

Atlas Note "NIEL and TID certifications of the active Dividers of the Tile Calorimeter of the ATLAS detector for the Phase II upgrade ATL-COM-TILECAL-2014-074 (Submitted) [Argonne + Clermont-Ferrand authors] 44 pages

8

• R&D completed with success.
• Production/Certification of 350 active Dividers for ATLAS 2015

(Cracks et MBTS).

• Test Bench refurbished for both passive/active Dividers

ready for future productions.

• ATLAS decision to come about a partial/total replacement

for the upgrade.

• Clermont-Fd will provide all information and software drawing

plus the Test Bench, to the Institute ready to make the production.

9

• Conclusion