1

Radiation worries in the Radiation worries in the caverncavern

L.Jirdén 17.6.02L.Jirdén 17.6.02

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AccessAccess

~55m

PLUG

ALICEDETECTOR

CR1

CR3CR2

CR4

ACR

BEAM

~50m

~15m

Cavern only accessible during shutdowns !

3

Magnetic fieldMagnetic field

~55m

PLUG

ACR

BEAM

~50m

~15m

0.5 T

No impactStray fields, impact ?Shielding DC/DC’s, etc

Two main magnetsL3 and MUON dipole

4

Radiation levels in Radiation levels in ALICEALICE

Simulation made by B.Pastircak 3 main sources:

Particle production at interaction point: 90% Beam-gas interactions: 10% Beam loss at injection: 1%

Conditions Global running scenario PbPb, CaCa, pp Geometry as known early 2002

Results Normalized to 10 years normal operational scenario Total dose [krad] Fluency [n*cm-2] Rack on the floor ~ 1 ~109

Rack 12m above floor ~ 0.006 ~107

5

Radiation levelsRadiation levels

~55m

PLUG

ALICEDETECTOR

ACR

BEAM

~50m

~15m

200 175 rad hard el. required 2 4.3 COTS ok, SEU strateg 1 0.9 SEU strategy ?0.006 0.0006 minor effects?

racks in c-rooms

gas distribution

racks in cavern

dose n.fl.Krad E10 n/cm2

6

7

Radiation testsRadiation tests

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9

ConsequencesConsequences Test by experiments

Extensive tests of “on-detector components” Very few tests of ALICE “cavern components” ATLAS ELMB test since 3 years Wiener Power supplies, CAEN DC/DC

Test of equipment by LHC machine Ongoing effort since 5 years Wide range of equipment tested

power supplies, PLC’s, sensors, gagues, vacum equipment, etc Mainly using TCC2 facility Levels in LHC tunnel and ALICE cavern similar? To be checked!

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SPS - North SPS - North Experimental HallExperimental Hall

TCC2 Hall and Beam Lines

TAX collimatorM2 beam line

T6 TargetRadiation Damage Test Area

LHC tests

11

Modular Power SuppliesModular Power Supplies Denis Hundzinger - SL/PO Denis Hundzinger - SL/PO

Test of 3 Different Technologies: Serial Regulation Switching with Bipolar, Transformer Coupling Switching with MOS-FET, Transformer Coupling

28 Units Tested – 11 Types – 6 Manufacturers

Remarks: Some Units Do Not Restart after Switch-Off Output Voltage Drifts With or Without Input Power

LHC tests

12

Switching Switching Power SuppliesPower SuppliesType: - VERO PK55 (2 Modules)

- Triple Switching

+ 5V/5A and 2x 5-15V/1A

Notes:- Measurement on 5 Volt Output Only

- Load = ~ 4 Amp

- Output Voltages increase with the Radiation Dose

- Both 5 Volt Output Voltages Start to Deteriorate at ~ 5 Grays

~ 5 Gray

~ 540 Gray

LHC tests

13

Preliminary ResultsPreliminary Results

PLC - First Error (Isolated Effect) at < 1 Gy - After Reload, Systematic Memory Error 4-8sec. 5 Gy - No Reply 20 Gy Edwards Gauges (With Integrated Electronics) - Gauge AIMX-X 50 Gy - WRG-S 1000 Gy Balzers Gauges - 2 Gauges PKR 251 290 Gy and 430

Gy - 1 Gauge PKR 265 450

Gy

LHC tests

14

Lessons LearnedLessons Learned Electronic Equipment that Will not Work Reliably

in the LHC Tunnel:

Intelligent Sensors and Actuators (Few Exceptions)

(Remote Electronics and Cables Required)

Complete Industrial PLCs (COTS)

Intelligent I/O Modules (COTS) with Micro and Memory

Conventional Switching Power Supplies (NMOS)

Processors Without Error Correction Memory

LHC tests

15

Lessons LearnedLessons Learned LHC Electronic Equipment That Needs to be Tested

before Installation:

Passive Components (Optical Fibers, Resistors, Capacitors)

Active Components (Signal Conditioners, MUXs, Op.-Amp.,

ADCs, DACs, FPGAs, EPROMs SRAMs with EDAC)

Sensors, Actuators, Gauges, Positioners,Valves, Flowmeters

Modular Power Supplies (Serial Regulation, Bipolar Transistors,

Transformer Coupling Feedback, No OptoCouplers)

LHC tests

16

Lessons LearnedLessons Learned RadHard Developments are Required for:

Simple Input/Output Modules with Fieldbus Interfaces to WorldFIP or Profibus (Command/Response Operation)

Dedicated Power Supplies (Quench Protection) Orbit Corrector Power Converters Control Processors with EDAC Memory and

Remote Reset Capability.

LHC tests

17

ConclusionsConclusionsPresent Results Suggest that ALL Electronic

Systems, Intended for Installation in the Tunnel, Should be Radiation Qualified

The Radiation Test Facility is Qualified to Provide a Radiation Environment

Similar to That of the LHC Tunnel (Arcs)

The On-Line Test Facility can be Used for the Final Qualification of Complete Working

Systems

LHC tests

18

What equipment is planned What equipment is planned for ALICE cavern?for ALICE cavern?

Power distribution (Hazemeyer) + control Network equipment LV supplies

CAEN 1527, Wiener PL500, AREM Pro, Eutron, ? HV supplies

CAEN 1527, ISEG, ? Gas

Distribution for some detectors Cooling

Cooling plants & its control Detector cooling I/O

VME Crates and modules

Others?

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ConclusionConclusion More detailed simulations needed Effects (at middle and low levels) to be

better understood Strategy to be defined Possibility to move equipment from UX to

PX? Systematic qualification of “cavern

equipment”? Who does what?