evaluation of radiation to machine components and equipment

EVALUATION OF RADIATION TO

MACHINE COMPONENTS AND

EQUIPMENT

HL-LHC Standards and Best Practices WorkshopJune 13, 2014

M. Brugger, F. Cerutti, L.S. Esposito, A. Ferrari,

A. Lechner, A. Mereghetti, N. Shetty, E. Skordis, V.

Vlachoudis

N. Mokhov, I. Rakhno, I. Tropin

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QUITE A BIT OF ENERGY

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

9.5 kW delivered in collisions (L=5L0)

on each side of ATLAS and CMS, a 54mm aperture TAS absorber takes 500Wand let 3.5kW impact the machine

54 mm

5 mm

21 m

by design, up to 500 kW can impact the primary collimators (in IR7)

700 MJ per beam (7 TeV protons, 2.2 1011 p per bunch, ~2800 bunches)

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WHICH IMPACT

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

radiation sources: regular collisions, collimator cleaning, beam-gas interaction

various accident scenarios (e.g. UFO)

Heating, stress energy (power) deposition

Degradation energy (dose) deposition, particle fluence, DPA

Monitor response energy (dose) deposition (→ charge collection), particle fluence

Background particle fluence

Electronics high energy hadron fluence, neutron fluence, energy (dose) deposition

Activation residual activity and dose rate

thermomechanical analysis where needed

S. Roesler’s talk

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FROM MICROSCOPIC …

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

interplay of many physical processes described by different theories/models

integrated in a Monte Carlo code

multiple scattering

hadron-nucleusreaction

particle decay

low energy neutronreaction

ionization

electromagneticshower

6 GeV proton in liquid argon

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… TO MACROSCOPIC

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

proton beam on a 1 m long and 10 cm radius copper rod

160 MeV 7 TeV

LINAC4 and LHC

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MACHINE MODEL

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

in principle any relevant object can be implemented to a meaningful detail

FLUKA Element Database

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LINE BUILDER

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

IR7, generated from the optics lattice

A. Mereghetti et al., IPAC2012

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IR1

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

Tracking accuracy within one micronover several hundred meters in a 3D geometry

with various magnetic fields

Long Straight Section and Dispersion Suppressor Right of ATLAS

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HL-LHC IR IN FLUKA

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

beam screen gap (10 or 50 cm)in the middle of the interconnects

CPD1

Q3TAS

150mm(coil) aperture

10F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

HL-LHC IR IN MARS

D1

Q3

Q2BQ2A

Q1TAS

CP

IP

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DOSE TO THE BEAM SCREEN

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

several hundred MGy over the machine lifetime

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QUADRUPOLES, CORRECTORSAND SEPARATION DIPOLE

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

dose in the coils

critical dependence on the actualInermet shielding shape and gaps

700 W in the cold masses + 550 W in the beam screen + 1.2 kW in the TAN

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NOT HOMOGENEOUS DISTRIBUTION

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

[GeV/g per collision]

monitor signal

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BLM MEASUREMENTS AND SIMULATIONS

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

[† input from V. Chetvertkova et al.]

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LOOKING FARTHER FROM THE BEAM

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

Power Supply 24VDC 5A

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RADIATION EFFECTS ON ELECTRONICS

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

Intermediate energy neutrons: low energy elastic/inelastic products

Inelastic interactions

Thermal neutrons:n+10B→7Li+4He

Low energy charged hadrons: direct ionization (relevant for very sensitive technologies)

17F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

relevant physical quantitythe effect is scaling with

Single Event effects

(Random in time)

Single Event Upset(SEU)

Memory bit flip (soft error)Temporary functional failure

High energy hadron fluence [cm-2](but also thermal neutrons!)

Single Event Latchup

(SEL)

Abnormal high current state Permanent/destructive if not protected

High energy hadron fluence [cm-2]

Cumulative effects

(Long term)

Total Ionizing Dose(TID)

Charge build-up in oxideThreshold shift & increased leakage currentUltimately destructive

Ionizing dose [Gy]

Displacement damage

Atomic displacements Degradation over time Ultimately destructive

Silicon 1 MeV-equivalentneutron fluence [cm-2]{NIEL -> DPA}

RADIATION EFFECTS ON ELECTRONICS

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TEST, MONITOR, MITIGATE AND PREDICT

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

Numerous systems with commercial components are affected(powering, control, cooling, monitoring, etc.), several are critical for beam operation, some have to be located in “high-radiation” areas

Presently about 50 different system, half of them undergoing new developments, others upgrades.Number of parts per system range from a few to a some thousand

Reliability = low number of failures → short down-times!

devicesdevicesfailures NXxNdxxxN )(~)()(

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BEST PRACTICES

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

Radiation tests are a phase of a new component developmentRadiation constraints to be considered from day-0

REQUIREMENTS

Electrical system

Radiation environment and effects

Timeline

Com

plex

ity

DESIGN

Specifications

SelectionDesign

Time

TESTSystem

ComponentQualification

PROCUREMENT

Test boardsPrototypeProduction

20F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

LOOKING FARTHER FROM THE IP

D2: 65 Win its Nb-Ti coils peaks of 2 mW/cm3 @ 5L0 and 35

MGy /3000 fb-1 (to be improved)

protection based onthe TAN absorber, TCL debris collimators and tungsten masks

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ANOTHER ELECTRONICS ALCOVE

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

FH>20MeV [cm-

2](L2012)

5RM08S 5RM09S

FLUKA 6.1 108 3.0 107

DATA 4.56 108

(256 upsets)4.32 107

(25 upsets)Agreement within 30%

23 fb-1 @ 4+4 TeV

250 m downstream CMS

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CONCLUSION

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop

Currently used physics and geometry models allow to reliably simulate secondary particle showers to many purposes (beam intercepting device design, cold and warm magnet protection, monitoring, radiation to electronics, operation assistance, background, …, activation*). *next talkThink about the radiation field and let us know if you need its characterization.Systematic uncertainties imply to consider suitable design margins.

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WHATEVER

F. Cerutti June 13, 2014 HL-LHC Standards and Best Practices Workshop