single event upset vulnerability - radiation...
TRANSCRIPT
OUTLOOKOUTLOOK
h bl2
The problemOverview of LHC points and prioritiesCriticality
By areaBy equipment
The strategy for the future:Working groups and organisationRadiation MonitoringHow to develop a new culture
Conclusions
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The ProblemThe Problem
Si l E t U t t d b hi h3
Single Event Upsets are generated by high energy hadrons (typically >20 MeV) They generally corrupt memory registers or induceThey generally corrupt memory registers, or induce spurious signals that can lead to Single Event ErrorsSingle Event Upsets lead to Single Event Errors g p g(equipment failure, component burn-out etc…), if no precaution is taken in the selection of electronic component and designcomponent and design.Commercial Off The Shelf (COTS) electronics is generally not immune by itself to SEU, but in few cases g y y ,can be hardened by re-programming or by using hardware redundancy.
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The ProblemThe Problem4
Failure in some COTS electronics in CNGS in Oct. 2007 triggered an investigation in LHCAt the base of the problem there are 2 main causes:
Several areas were declared as “radiation free” because the dose was low, but hadron fluence remains because e dose was ow, bu ad o ue ce e a sconsiderable. The level of awareness of the problem was low, inThe level of awareness of the problem was low, in particular in groups not having equipment in areas not classified as radioactive.
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The ProblemThe Problem5
In 2008, the R2E team assessed the most critical areas, recommending either shielding or moving equipment from most critical areas to cope with increasing intensity and luminosity in LHCStarted to organise the approach across different departments to avoid “panic” mode.departments to avoid panic mode.
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The ProblemThe Problem6
In most of those areas (e.g. UJ76) dose (1 MeV eq.) is “negligible” (no more than few gray/year)
Disclaimer: numbers as of end 2007.
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
UJ76 Examples – Downstairs
7
UJ76
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Overview of LHC points and prioritiesOverview of LHC points and priorities8
Work documented in a website, for the moment with restricted accesshttp://ab-div.web.cern.ch/ab-div/Meetings/r2eThe database contains:The database contains:
Existing simulationsD i d l t i l di k iti dDrawings and layouts, including rack position and compositionR di i i i h (RP R d BLM )Radiation monitors in the area (RP, Radmon, BLMs …)Any other useful information
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Overview of LHC points and prioritiesOverview of LHC points and priorities9
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Overview of LHC points and prioritiesOverview of LHC points and priorities10
Maximum priority was set to UJ76 (at nominal intensity 1 SEE every few minutes)RR76/RR77 UA63/67 (to protect dump system controls)/ 7 ( p p y )Cryo equipment in UX85
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Overview of LHC points and prioritiesOverview of LHC points and priorities
SO ONS11
SOLUTIONSUJ76:
M t d TZ76 hi ldi ibl ( t f )Move towards TZ76: no shielding possible (apart safe room). Civil engineering and cabling works on-goingEquipment will be moved only after first shutdown – no time to q p ymove -recommission
RR76/RR77 C l h ld f llComplete shielding as foreseen initially
UA63/67 (to protect dump system controls)ShieldShield
Cryo equipment in UX85Replace with existing rad-hard solutionp g
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Overview of LHC points and prioritiesOverview of LHC points and priorities12
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Overview of LHC points and prioritiesOverview of LHC points and priorities13
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
CriticalityCriticality14
First prioritySEE should not compromise safety of the machine and personnel
Priority (if needed) will be given to equipment that enter into the machine protection scheme and AL3
Second prioritySEE should not lead to downtime
Then all the othersThen all the others
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Criticality by areaCriticality by area15
[ Loss/Intensity-Scaling: M. Lamont] LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
Criticality by equipmentCriticality by equipment16
Movable Detectors
Beam LossMonitors
BCM
Experimental Magnets
CollimatorPositions
Environmentalparameters
Special-
LHCDevices
LHCDevices
LHCDevices
Safe Beam Parameter Distribution
B
LHCExperiments
CollimationSystem
Transverse Feedback
Beam ApertureKickers
pBLMsOperator
ButtonsCCC
SafeLHC
Parameter
SoftwareInterlocks
Sequencer
Beam Interlock SystemBeam
Dumping SystemInjection
P P M B S /A VB l
SafeBeamFlag
jInterlockPowering
Interlockssc magnets
PoweringInterlocks
nc magnets
Magnet Current Monitor
RFSystem
BeamLifetimeFBCM
Screens / Mirrors
BTV
Access System
VacuumSystem
Beam loss monitors
BLM
M it M it
Timing System (Post Mortem
Trigger)
QPS Power AUG UPS
Power Converters
Magnets
Cryo Doors EIS Vacuum Access RF
Monitorsaperture
limits(some 100)
Monitors in arcs
(several 1000)
Trigger)
QPS(several 1000)
Power Converters
~1500
AUG UPS CryoOK
Doors EIS Vacuumvalves
AccessSafetyBlocks
RF Stoppers
© R. Schmidt, M. BruggerLHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The Strategy for the futureThe Strategy for the future
P li f El t i LHC M hin C itt17
1. Policy for Electronics installed in areas with elevated radiation levels
LHC Machine Committee
(R2E)2. Evaluation of Radiation
Levels: simulationsR2EPoint-
OwnersLevels: simulations, monitoring, proposal of measures (R2E)S i l
RadWG
T ti
Monitoring
3. Structure to implementthe Policy (RadWG)
4 Radiation TestsEquipment
Owners
Testing
4. Radiation Tests (RadWG)
5. Control (Point Owners)Installations
Electronics PolicyElectronics Policy
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The Strategy for the futureThe Strategy for the future18
R2E Improve knowledge of “as built” caverns and identify equipment installed
Point owners (with the help of R2E members and equipment owners) in charge of filling the database
RADWG Improve knowledge of sensitivity of equipment installedq p
Equipment groups to name representative in RADWG to follow up on technical aspectsfollow up on technical aspectsTest equipment for which sensitivity is not known.
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The Strategy for the futureThe Strategy for the future19
RADWG – Radiation testsWill steer testing process through
component testing in monoenergetic beamsSystem testing in CNGS irradiation facility
Efficiency limited by available manpower and beam time in facilities need to increase and differentiate resources.Test know-how centralised in EN/STI to cope with urgent work, but every group should little by little acquire some know-how (as e.g. PO, QPS etc…).
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The Strategy for the futureThe Strategy for the future
M20
Radiation MonitoringCombine data from all available radiation monitors (BLM RP RADMON ) i i l i f i h(BLMs, RP, RADMONs) in one single interface with coherent unitsCompare with simulationCompare with simulationCorrelate with known equipment failuresDefine new needs for monitorsDefine new needs for monitors
Application will be available in CCC for beamApplication will be available in CCC for beam commissioning
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
The Strategy for the futureThe Strategy for the future21
How to develop a new culture:Only a few groups have already a very good knowledge of the problem and how to cope with itRaise awareness by having a clear policy, to which directors, department heads and group leaders should commit.In particular, each group shall have a linkman, participating to RADWG and diffusing information in the groupSpecific training will be organised (one day school)
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
ConclusionsConclusions22
Single Event upset can compromise operation of LHC as intensity and luminosity increaseWe are however out now from “panic” mode, we have an understanding of the most critical problemsg pWe are setting up a structure (R2E, RADWG) that will help groups to get out of the “tunnel”will help groups to get out of the tunnel
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI
ConclusionsConclusions
W d bl 200923
We do not expect serious problems in 2009AL3 systems still under investigation
NNext problems :Power converters in RRs: solutions under study to implement “simple” modifications Shutdown 2010/11 ?simple modifications. Shutdown 2010/11 ?UJ14/UJ16/UJ23/UJ56/UJ87/US85…, RRs: several equipment concerned (access, collimation, BICs). Additional q p ( , , )shielding or relocation under study. Possible few problems in 2010, depending on luminosity and intensity.
Solutions to be found in 2009, implementation depending on operation experience and time.
LHC Risk Review, 5/3/2009Single Event Upset Vulnerability, R. Losito EN/STI