Colmar Setember 2002 M Dentan Ph Farthouat Radiation

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Assurance in the LHC experiments Martin Dentan CEA Saclay Philippe Farthouat CERN With the help of Francis Anghinolfi Jorgen Christiansen Mika Huhtinen Peter Sharp Giorgio Stefanini 1

Colmar Setember 2002 M. Dentan, Ph. Farthouat Outline u Radiation Issues u Radiation constraints in the experiments u Radiation hardness assurance in the experiments u A few examples of difficulties u Conclusions 2

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Issues (1) u Cumulative effects – Total Ionising Dose (TID) » Energy deposited in the electronics by radiation in the form of ionization. » Unit: Gray (Gy), 1 Gy = 100 rad » Affects all electronics devices – Non Ionising Energy Loss (NIEL) » » Displacement damage Unit: particles/cm 2 Complex radiation 1 Me. V neutrons equivalent CMOS devices are not affected 3

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Issues (2) u Single Event Effect (SEE) – Destructive effects: SEL, SEB, SEGR, … – Upsets: SEU (logic), SET (linear) – Instantaneous effect: may occur just after the beam is switched on. 4

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Issues: TID u u u Charge trapping in oxides and interfaces Vt shift, change gm, leakage current, noise, … Cumulated damage => delayed effect Dose rate and temperature dependence Effects on MOSFETs, BJTs, diodes, … May appear after only few krads 5

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Issues: NIEL u u u Bulk defects in semiconductors , noise, … Cumulated damage => delayed effect Effects on bipolar devices No effect on MOSFETs 6

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Issues: SEE u u Energy deposition in the component Can change the state of logic node (SEU) or generate transients in linear circuitry (SET) Can trigger parasitic components and generate latch-up (SEL), burn-out (SEB), . . A work done by M. Huhtinen, F. Faccio has shown that only the hadrons of E > 20 Me. V have to be considered 7

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation constraints: ALICE u TID (10 years) – 2. 5 k. Gy (pixels inner layer @ 3. 9 cm radius) – 1 Gy (in the experimental hall) u NIEL (10 years) – 2. 1012 n. cm-2 (pixels inner layer @ 3. 9 cm radius) – 108 n. cm-2 (in the experimental hall) u. Radiation levels: internal note with updated calculations –A. Morsch, B. Pastircak (to become available end Sept 02) 8

Radiation constraints: ATLAS u TID (10 years) – 3 MGy (Pixels) – 5 Gy (Cavern) u NIEL (10 years) – 2 1015 n. cm-2 (Pixels) – 2 1010 n. cm-2 (Cavern) Colmar Setember 2002 M. Dentan, Ph. Farthouat u SEE (10 years) – 3 1013 h. cm-2 (Pixels) – 2 109 h. cm-2 (Cavern) – h > 20 Me. V 9

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation constraints: CMS u TID (10 years) – 8 MGy (Pixels) – 5 Gy (Cavern) u NIEL (10 years) – 2. 5 1015 n. cm-2 (Pixels) – 2 1010 n. cm-2 (Cavern) u SEE (10 years) – 3 1013 h. cm-2 (Pixels) – 2 109 h. cm-2 (Cavern) – h > 20 Me. V 10

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation constraints: LHCb u TID (10 years) – 0. 1 MGy (vertex) – < 100 Gy (cavern) u NIEL (10 years) – 1015 n. cm-2 (vertex) – 2 1012 n. cm-2 (cavern) 11

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation constraints: summary u ATLAS and CMS are very similar – 10’s of MRad in the trackers – 1000 k. Rad in the calorimeters (Em) – A few k. Rad in the muon spectrometers and the caverns u LHCb – A few Mrad in the vertex – A few k. Rad in the calorimeter and muon » Although the muon electronics has more u ALICE has lower levels – 250 k. Rad in the pixel – Less than a k. Rad in the cavern – SEE have still to be taken into account 12

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Hardness Assurance u u Goal: reliability of the experiment with respect to radiation The radiation hardness assurance methods must be applied to each sub-system of the experiments – Particular attention should be paid to the identification of critical elements and to the possible failure modes u Should be coherent – Same rules for every system u Apart for the tracker electronics, there are differences between the experiments 13

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation hardness for inner trackers u Very uniform policy within the four experiments – Use of radiation hard technology (DMILL) – Use of DSM technology with a rad-hard lay-out – Very strict qualification for other components » e. g the optical links components u Status of design and production 14

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Hardness Assurance: Constraints u u Basis for the tests to be done Needed: – TID (Gy), NIEL (1 Me. V equiv. N. cm-2), “SEE” h. cm-2 (E > 20 Me. V) u Very desirable to have tools to get these constraints in small elementary domains – Averaging may lead to optimism 15

Radiation Hardness Assurance: Constraints Hot points (a few 10’s of ASICs) Colmar Setember 2002 M. Dentan, Ph. Farthouat Average constraint ATLAS MDT readout ASIC Leakage current versus TID 16

Colmar Setember 2002 M. Dentan, Ph. Farthouat Radiation Hardness Assurance: Constraints u Constraints from simulation tools (Fluka, Gcalor, Mars) – There are uncertainties due to the physics models, to the detector model, … – There are uncertainties with the electronics Safety Factors 17

Colmar Setember 2002 M. Dentan, Ph. Farthouat Safety Factors u Simulation uncertainties (location and type dependent) – – u ALICE proposes from 2 to 3 ATLAS ranges from 1. 5 to 6 LHCb uses 2 CMS quotes from 1. 3 to 3 Electronics effects – Low dose rate effects » ATLAS ranges from 1 to 5 depending on radiation type, technology and tests procedures (e. g. annealing at high temperature) – Lot to lot variation for the COTS » ATLAS ranges from 1 to 5 » LHCb ranges from 2 to 100 – Safety factors are there to flag possible problems u Dosimetry uncertainties – LHCb applies a factor 2 – Others trust the dosimetry 18

Colmar Setember 2002 M. Dentan, Ph. Farthouat Testing Procedures u Testing electronics against radiation is complex – – u Tests conditions Type of radiation Biasing conditions Annealing conditions Better to base the tests on standard methods – ESA or MIL u Tests to be done several times – Pre-selection – Qualification of production lots u Experiments policy – ATLAS has defined some testing procedures – LHCb is pointing to them 19

Colmar Setember 2002 M. Dentan, Ph. Farthouat Results book keeping u Very desirable to have a standard radiation test report – To be sure that nothing is forgotten – To be easily reviewed and shared u A central place to store them is also desirable – To share the results between different groups u A data base accessible through the WEB is available – Developed by Chris Parkman for ATLAS – Adopted by RD 49 i. e available for all experiments – Not sufficiently used 20

Colmar Setember 2002 M. Dentan, Ph. Farthouat Management u u Two main types Radiation Hardness treated centrally – One responsible for the experiment, One per sub-system, one per electronics entity (boards) – Common rules for everybody – Common rules for the reviews – Preselection and qualification processes u Radiation Hardness treated by each sub-system – As an extra specification – No specified rules u ATLAS is using the first model, CMS the second one 21

Colmar Setember 2002 M. Dentan, Ph. Farthouat Interpretation of the results u Assuming a perfect procedure has been applied we should know when launching the production – How the electronics will behave in time with respect to cumulative effects – What is the cross-section of SEE u The agreement for starting the production still needs some extra thinking – Can we have some maintenance for cumulative effects » Physical access and financial capability – Can we overcome the effects of SEE » In the design in implementing special techniques (e. g redundancy) » In the system in implementing reset sequences or continuous monitoring of the key data » In the power supplies for latch-up detection and automatic switch off » In just living with them (e. g data corruption) 22

Colmar Setember 2002 M. Dentan, Ph. Farthouat Interpretation of the results –cont. u u u The most difficult point concerns the SEE as this is a statistical process and that it is not needed to have high doses to be disturbed The experience that we have got in ATLAS is that there has not been a single SEE test not leading to problems FPGA are particularly sensitive – LHCb has issued a rule for using only antifuse FPGA and triple redundancy – Several systems are going to use ASICs or Gate Arrays instead of FPGA (ATLAS Liquid Argon and Muon trigger) or are moving the complexity at safer places (ATLAS Muon tracking, LHC machine) 23

Colmar Setember 2002 M. Dentan, Ph. Farthouat A few examples of difficulties u u u ATLAS Liquid Argon electronics and power supplies ELMB Low voltage regulators 24

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Electronics u Electronics in crates around the detector G’damm I am good! u Radiation Tolerance Criteria for LAr – TID = 525– 3500 Gy/10 yr – NIEL = 1. 6– 3. 2 1013 N/cm 2/10 yr – SEE = 7. 7 -15 1012 h/cm 2/10 yr 25

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Electronics u 1 responsible per board – – – – u FEB (1600 boards) : J. Parsons Calib (120 boards) : N seguin Controller (120 boards) : B. Laforge Tower builder (120 boards) : J. Pascual Tower driver board (23 boards) : E. Ladyguin LV distrib ( ) : H. Brettel Purity (? ) : C. Zeitnitz Temperature : ? 1 representant for power supplies – Helio Takai u 1 representant for optical links – Jingbo Yee 26

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Electronics u First tests made with COTS were very disappointing… u Decision to avoid them as much as possible A lot of extra design work 27

Liquid Argon Electronics: FEB 128 input signals 32 0 T Colmar Setember 2002 M. Dentan, Ph. Farthouat Analog sums to TBB 32 Shaper 2 LSB 14 pos. Vregs +6 neg. Vregs u 32 SCAC 2 DCU 16 ADC 8 Gain. Sel 1 Config. 1 SPAC AMS DSM COTS 1 MUX 1 GLink 7 CLKFO DMILL 1 TTCRx 1 fiber to ROD TTC, SPAC signals 10 different custom rad-tol ASICs, relatively few COTs 28

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Electronics: ASICs 29

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Electronics u u Tracking of the status of radiation hardness of components Still possible to forget a component – E. g opto-receiver of the TTC u Complete crate with radiation tolerant electronics to be ready in 2003 30

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Power Supplies u Each Test crate requires. Goal 3 k. W Achieved u 4 k. W DC-DC based power supply has been designed – To. Radiation be located inside the detector Ionizing 10 k. Rad 300 k. Rad – 300 V DC input 2 -3 years of measurement and development to understand solve radiation problems NIEL 1. 15 x 1012 5. 0 x 1013 u Most severe problem was SEB (Single Event Burn-out) u – SEB destroys the MOSFET. -16 cm 2 on the 11 – SEB depends on how the MOSFET is biased therefore Hadrons E>20 Me. V s. SEBand <1 x 10 5 x 10 topology of the power supply. Resonant circuits for -13 example s. SEL<7 x 10 cm 2 are particularly bad for SEB because VDS depends on the load – The second effect that one has to be aware is the asymmetric Magnetic Field G 120 nature of the SEB cross 20 section. When particles hit. Gfrom the drain side it can be significantly larger than from the gate side. This has been determined for ~6 different power MOSFET. 31

Colmar Setember 2002 M. Dentan, Ph. Farthouat Liquid Argon Power Supplies –cont. Still a Lot of Concerns !! u u u NOT because of loss of power supplies! SEB and SEGR are potential hazards that can short converters and failure in protection systems could lead to instant fire hazard. Power supplies are rated to 4 k. W. Note that they are located in places that are inaccessible in case of emergency. Ionizing radiation damage leads to loss of regulation and potentially loss of electronics. Magnetic Field saturates transformers and supplies ceases to work with possible short in the input stage. Unknown background is the one that will do the job. Currently SEB for pions, kaons are unknown but we know that SEE induced by pions can be 5 x larger than neutrons. Production of fragments in packaging, etc have not been considered. 32

Colmar Setember 2002 M. Dentan, Ph. Farthouat Embedded Local Monitor Box (ELMB) u u Basic element for the slow control of the ATLAS muon chambers CAN Voltage regulators Tranceiver Radiation constraints (including safety factors) – TID : 8. 4 Gy in 10 years; – NIEL: 5. 7 E 11 n/cm 2 (1 Me. V eq. ) in 10 years; ISP – SEE: 9. 5 E 10 h/cm 2 (>20 Me. V) in 10 years. ADC ATMEL micros REF Latch DIP-SW ID BAUD Logic 3. 3 to 5. 4 V option? Analog MUX 50 mm OPTOs VSup CAN SAE 81 C 91 67 mm 33

Colmar Setember 2002 M. Dentan, Ph. Farthouat ELMB –contu TID results: one of the processors is sensitive (although well within the requirements) 34

Colmar Setember 2002 M. Dentan, Ph. Farthouat ELMB –cont- u u SEE results: requirement for an automatic power on-off Care being taken for the use of the RAM – “SEE resistant” software 35

Colmar Setember 2002 M. Dentan, Ph. Farthouat ELMB –contu Additional work going on – Current design has two processors. Next will have only. Improved TID response – Software to counteract the SEE being improved u Production organisation – Qualification of batches of components u Safe definition of where the ELMB can be used: – TID > 40 Gy for protons – NIEL > 5*1012 neutrons/cm 2 – SEE >> MDT requirements 36

Colmar Setember 2002 M. Dentan, Ph. Farthouat Low Voltage Regulators u Radiation tolerant low voltage regulators (a few krad and a few 1012 n. cm-2) almost impossible to find – One from Intersil may be OK for ATLAS calorimeter but costs too much u RD 49 has initiated a development with ST Electronics – Positive and negative adjustable regulators – Very hard (several Mrad) u u Positive version available Negative version had a bug – Has been corrected – A few 100’s available in November (not lifetime qualified) – Quantities in January-February 2002 37

Colmar Setember 2002 M. Dentan, Ph. Farthouat Summary-Conclusions u Radiation Hardness is still an issue in the experiments – SEE is a major concern u u u The knowledge of the problems has reached a reasonably good level in the community thanks to tutorials organised either in the experiments or by RD 49 The radiation hardness assurance approaches are not identical in the experiments (or in the machine) Book keeping is a key issue if one wants to benefit from the work done – The existing data base should be more widely used – It requires a effort of documentation from all of us » Tests descriptions » Results 38