1. 11 JULY 2002Jacques Lefrancois1  History: Previous Montecarlo Calculations by V. Talanov I. Korolko=> about 100rads/year and about 10**9 neutrons/cm**2 per year >20 MeV Test at the ORSAY 200MeV proton cyclotron Calculation of effects on electronic (Machefert et al) (note 2002-21) As a consequence since last year redesign of electronics to be SEU proof  New Montecarlo calculation of radiation levels by L. Shektman using LHCb classic- and a safety factor of two for the flux => 200-300 rads per year typical We should understand the meaning of maximum=>*  LHCb radiation hardness policy for electronics given by J.Christiansen (May 2002 electronic meeting in LHCb week) =>* Radiation Policy for CALO electronics

2. 11 JULY 2002Jacques Lefrancois2 Update on radiation levels on May 2002 by Lev Shekhtman

3. 11 JULY 2002Jacques Lefrancois3 LHCb front-end meeting on May 2002 by Joergen Christiansen

4. 11 JULY 2002Jacques Lefrancois4 Calorimeter policy The Krad problem does not seem severe. The SEU problem is handled by the use of ACTEL and triple voting for key registers. The main remaining problem is SEL: it is very difficult to accumulate enough irradiation on a few chips in a proton beam to simulate 1000s of chips in LHCb neutron flux without exceeding the Krads limit =>* note LHCb 2002-021: test with ions Protect the cards and components by a resettable fuse

5. 11 JULY 2002Jacques Lefrancois5 FUSE = Polyswitch = polymer +carbon powder price 0.5 euro EX: 2.2 A normal state 0.2 volts drop, > 2.2A => large resistance limits current to < 1.1 A until reset of power supplies and cool down Q: is it rad hard? Is the 0.2 volts stable? If not is it creating problem in digital part? Is the protection good enough? Test with ions : SEU/SEL caused by recoil ions with large LET (6? to 15 MeV/mg) Largest LET produced by neutron (proton) interaction = 15 MeV/mg but the cross section is low. Testing with ions is more sensitive but computation is needed using neutron cross section. Test done with ions with LET of about 15 (58 MeV*A Krypton) Numbers for SEL life use assumption that SEL probability is flat between 6 and 15. This could be pessimistic

6. 11 JULY 2002Jacques Lefrancois6 Component Duration (s) Dose (krad) SEL equivalent (year) 1 3479 (~1h) 22.687 2 1643 (~1/2h) 10.741 31896(~1/2h)12.347 4 1800 (~1/2h) 11.745 Proton Irradiation at CPO

7. 11 JULY 2002Jacques Lefrancois7 Component # SEL Cumul. Time (s) Surf max 95%CL Surf min 95%CL P sel (neutron) Resistance (year.chip -1 ) Shaper016000 8.9x10 -9 - <1.8x10 -14 >14000 RAM04000 3.9x10 -8 - <7.8x10 -14 >3205 Serial 215/216 22521 1.3x10 -7 4.0x10 -8 <2.6x10 -13 >961 S. 215/216 Drv 91682 5.0x10 -7 1.3x10 -7 <10 -12 >250 Serial 483/484 72254 3.1x10 -7 5.7x10 -8 <6.2x10 -13 >403 S. 483/484 Drv 13 (13 ?) 8.1x10 -5 (?) 2.7x10 -5 (?) 1.62x10 -10 (?) >1.5 (?) Ion Irradiation at Ganil

8. 11 JULY 2002Jacques Lefrancois8 Recommended tests Idealy one should irradiate cards for a few 10**7 relativistic lead ions at the SPS. This tests all components and the most severe SEL and SEU conditions with about 20 Krads of TID. However the last SPS ion beam period is in autumn 2003 cards may not be ready. ALL components could instead be tested at Ganil or GSI or at a cyclotron proton beam CPO or Louvain However the use of protons may require many components to have enough statistics

9. 11 JULY 2002Jacques Lefrancois9 Components tested & to be tested Main components already tested PS/SPD and ECAL/HCAL amplifier-integrator Multiplexers (drivers and receivers) Memories (32K 16bits) Actels To be tested: Other memories (L1 buffer +?) Line drivers Variable delay chip Others??? (fuse+…) A common test is the only efficient procedure=> : when?