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Performance of Injection Protection Systems V.Kain AB/CO. Contents SPS Extraction – Transfer – LHC Injection Injection Protection System Principle Passive Protection Interlocking Simulations for Protection Level Conclusions. - PowerPoint PPT Presentation
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4/12/2005 Verena Kain, AB-CO 1
Performance of Injection Protection Systems
V.Kain AB/CO
Contents •SPS Extraction – Transfer – LHC Injection •Injection Protection System Principle•Passive Protection•Interlocking•Simulations for Protection Level•ConclusionsInput from B. Goddard, R. Genand, R. Schmidt,J. Wenninger, M. Werner
4/12/2005 Verena Kain, AB-CO 2
SPS Extraction – Transfer – LHC Injection
Beam 2
Beam 1
Injection Process
LSS6/TT60 TI 2 LHC injection LHC SPS
TE
D T
T60
TE
D T
I2
TD
I IR
2
MKE MKI
IR2 BEAM1
Extraction Transfer Injection
TED…beam stopper in transfer lineTDI…injection stopper in injection region
To define the Injection Protection System, SPS Extraction, Transfer and LHC Injection must be treatedtogether.
SPS:MSE…extraction septumMKE…extraction kicker
LHC:MSI…injection septumMKI…injection kicker
BEAM2: LSS4/TT40 – TI 8 – IR 8
4/12/2005 Verena Kain, AB-CO 4
Injection/Extraction Constraints
Inside, damage visible over ~1m (melted steel)
8x1012p+ = ¼ of full batch
Holes in Cu : 450 GeV p+ beam(from 2004 TT40 materials test)
5.3x1012p+ = 1/6 of full batch
• Damage limit:~2x1012p+, ~5 % of injected batch
• Small Aperture:– 7.5 LHC aperture at 450GeV– Tight aperture in transfer line (MSI injection septum ~7)
Full nominal injected LHC batch: 3.3x1013p+, 450 GeV
4/12/2005 Verena Kain, AB-CO 5
What can go wrong: magnet trips, kicker failures, wrong
settings…
• Magnet trips can move trajectory by many in short time (MSE extraction septum: 40 in 1ms)• Kicker erratics, missings, timing etc.• Operator error• Corrupted settings
10 cm~25cm long hole in QTRF chamber
Extraction septum (MSE) trip during high intensity extraction, Oct 2004
Slow failures:10 in > 2-3ms: relying on interlocking
Fast failures:10 in < 2-3ms: interlocking + collimators
Ultra-fast failures: 10 in few s: collimators
Injection Process
4/12/2005 Verena Kain, AB-CO 6
Principle of Machine Protection for Injection
Process
ProtectionHW surveillance:PCS, FCCM, settings monitoring,equipment status
LocalBIC
MasterExtr./Inj.BIC
Failu
re,
Err
or
eff
ect
on:
HW
Beam Collimators, Absorbers
Inj./Extr.Inhibit
ACTIVE
PASSIVE
AvoidanceProcedures to avoid dangerous situationse.g. never inject high intensity beam in empty LHC
Beam Presence Flag → protects against many failures
4/12/2005 Verena Kain, AB-CO 7
Passive Protection for fast and ultra-fast failures
• Protection of LHC aperture and MSI injection septum aperture: – TCDI collimators for failures upstream of injection
regions– “generic” protection system with full phase coverage
• Dedicated collimators for kicker failures:– MKI (LHC) failure: TDI beam stopper + TCLI
collimators are 90° downstream – MKE (SPS) failure: TPSG diluter is 90° downstream
• No dedicated collimators for septum failures– Protection from MSE and MSI failures interlocking
4/12/2005 Verena Kain, AB-CO 8
TCDI Transfer Line Collimators
• Close to LHC and injection septum (last 300m matching section of TLs)
• Robust, based on LHC collimator design (1.2m C jaw)
• FLUKA model of 300m of TI 8 local shield for each TCDI
x’
x
0-60-120 degree collimators
60o120o
LHC apertureto protect at7.5
amax
6.9
• 3 collimators / plane (0-60-120°)
• Setting: 4.5, tolerances: ≤1.4
• 2 motors/ jaw (angular control)
• Protection level 6.9: result from comprehensive Monte-Carlo simulation including all imperfections: beat, mismatch from SPS, tolerances,…
6
4/12/2005 Verena Kain, AB-CO 9
TDI injection stopper, TCLI collimators
• TDI injection stopper:– Protect LHC (especially D1) against MKI kicker failures– 90° downstream of the MKI ~4m long hBN+Al+Cu jaws– local protection of SC LHC magnet D1 with mask -> TCDD (1m, Cu)
• Auxiliary collimators TCLIs – For MKI-TDI phase advance ≠90°, and for flexibility (halo load…)– At nx180°±20° from TDI (1.2m long C jaws)
MKI
Overview, vertical plane: functionality of TDI injection stopper
orbit
4/12/2005 Verena Kain, AB-CO 10
TDIMKI +90˚
TCDD
TCLIBTDI +340˚
TCLIATDI +200˚
KickerMKI
LEFT OF IP2
RIGHT OF IP2 TCLIM
TDI – TCDD - TCLI
Topview
4/12/2005 Verena Kain, AB-CO 11
Interlocking for Extraction – Transfer -Injection
• Segmented Interlocking System, different possible operational modes in a safe way– e.g. Extraction without injection, IF TED (transfer line
beam stopper) in the beam
• Without “LHC injection permit” NO “SPS extraction permit”
• Beam Presence condition for high intensity injection
• Safe Beam Flag: “maskable” interlock signals are ignored
4/12/2005 Verena Kain, AB-CO 12
Interlocking System: linking injection with extraction
LSS6/TT60 TI 2 upstream TI 2 downstream LHC injection LHC SPS
SP
S e
xtra
ct p
erm
it
SPS MKE extract
SPS LSS6MASTER
BIC
LHC IR2 injection
BIC
TI 2 upstream
BIC
TI8
ups
trea
m
TE
D T
T60
TE
D T
I2
SPS MKDdump
SP
S b
eam
per
mit
SPS ringBIC
SP
S r
ing
UP
s
SPS LSS6/ TT60BIC
LSS
6/T
T40
UP
s
SPS safe intensity flag
TD
I IR
2
UP
s
TI 2 downstream
BIC
TI8
dow
nstr
eam
LHC ringBIC
dumpLHC MKD
LHC
bea
m p
erm
it
LHC
inje
ctio
n
UP
s
Includes TI 2 after TED
TI 2 interlocking
LHC
inje
ct p
erm
it
LHC MKIinject
LHC safe parameters
4/12/2005 Verena Kain, AB-CO 13
Protection level simulations to quantify system
performance
• Extensive tracking simulations to check performance
• MKI kicker failure scanned with injection absorber setting
• Full Monte Carlo of single and grouped failures at injection
– 14 magnet and kicker families (SPS extraction, Transfer Line, LHC injection) for LSS4 - TI 8 – IR8
– Full TL + LHC injection region aperture model (~3 km)
– All imperfections and errors included
Safe LHC injection losses on aperture below 5% damage limit during injection
4/12/2005 Verena Kain, AB-CO 14
Injection kicker failure simulation results
• TDI, TCLI collimator setting of 6.8, to guarantee max. 5% above 7.5
• Increasing collimator opening increases risk of damage
N/N0 of particles with amplitudes >7.5 y
6.8
4/12/2005 Verena Kain, AB-CO 15
Single failure tracking Monte Carlo results (1000 seeds per
failure)Family Tolerable
error[k/k0]
required reaction time
[ms]
Covered by
LHC TL
MPLH (LSS4 bumper) 0.185 201.0 TCDI PCS
MKE (LSS4 kicker) 0.125 - TCDI -
MSE (LSS4 septum, =23ms) 0.005 0.1 TCDI FCCM
MBHC (TT40 H bend) 0.005 5.1 TCDI FCCM
MBHA (TT40 H bend) 0.012 31.47 TCDI PCS
MBI (main TI 8 bends) 0.003 2.7 TCDI FCCM
MCIBH (start TI 8 H bend) 0.630 389.0 TCDI PCS
MBIAH (end TI 8 H bend) 0.003 7.9 FCCM FCCM
MBIBV (end TI 8 V bend) 0.003 43.4 PCS PCS
3MCIAV (end TI 8 V bend) 0.183 98.43 PCS TCDI
MSI (LHC injection septum) 0.0035 3.5 FCCM n/a• PCS = standard Power Convertor Surveillance (≥3ms)• FCCM = Fast Current Change Monitor, dedicated new system
Grouped Failures: Powering Scheme for Extraction – Transfer – Injection (beam2)
MBIAV
MBI
MBHA
MSE
BA418kV/660V
18kV/877V
18kV/560V
18kV/100V
MBIAHSR818kV/570V
MBIBVMSIB and A
18kV/400V
MBHC4001QTLF4004MCIBH8040MQID8010MQIF8020MQID8030
18kV/400V
MQIF18kV/660V
MQID18kV/660V
MQIF8720MQID8730MQIF8740MQID8750MQIF8760MQID8770MQIF8780MQID8790MQIF8800MQID8810
18kV/400V
MDSV4002QTRD4003
18kV/400V
QTRF4002QTMD4001
Grouped Failures
MBIAV
MBI
MBHA
MSE
BA418kV/660V
18kV/877V
18kV/560V
18kV/100V
MBIAHSR818kV/570V
MBIBVMSIB and A
18kV/400V
MBHC4001QTLF4004MCIBH8040MQID8010MQIF8020MQID8030
18kV/400V
MQIF18kV/660V
MQID18kV/660V
MQIF8720MQID8730MQIF8740MQID8750MQIF8760MQID8770MQIF8780MQID8790MQIF8800MQID8810
18kV/400V
MDSV4002QTRD4003
18kV/400V
QTRF4002QTMD4001
B
A C
D
E
Grouped failure tracking Monte Carlo results (1000 seeds per
failure)Group Tolerable time
after switch-off [ms]
Covered by
LHC TL
A 1.3 TCDI FCCM on MBHC (0.1% tolerable
error)
B 0.1 TCDI FCCM on MSE
C 15.8 TCDI PCS
D 3.5-5.8, > 20 FCCM on MSI TCDI/PCS
E 4.0-5.4, > 20 FCCM on MBIAH, MSI
FCCM on MBIAH(0.15% tolerable
error)• In some cases grouped failures can be ~ 5 times worse than single failures
• e. g. MBHC• Grouped failures covered with protection for single failures BUT: requires increased performance
4/12/2005 Verena Kain, AB-CO 19
Discussion of results• Fast magnet Current Change Monitor (FCCM) is required
– Specification: I/I=0.1%, reaction time ~50s
• With FCCM at the MSI injection septum LHC protection looks OK
• Transfer Line (TL): FCCMs are proposed for MSE, MBI, MBIAH, MBHC– MKE extraction kicker faults can still cause damage to the TL…
possible solutions being studied.
• All other single failures are covered for Transfer Line & LHC– Transfer Line collimation system (TCDI) gives full
protection from upstream failures– Failures at end of line: slow enough for normal power
converter surveillance or FCCM
• Grouped Failures: can be ~ 5times faster than single failures– Covering single failures also covers grouped failures– But needs increased surveillance system performance
4/12/2005 Verena Kain, AB-CO 20
Fast Current Change Monitor for MSE extraction
septum
• Managed to detect I/I<0.3%, reaction time < 50 s
– larger ripple on test-bench MSE power supply than real circuit (0.17% instead of 0.04%)
• Looks promising, needs to be finalized
FCCM tested for MSE by M. Werner from DESY this month FCCM
MSE test-bench
FCCM measures changes of magnetvoltage: no comparison with reference value
FCCM
4/12/2005 Verena Kain, AB-CO 21
Conclusions
• Tracking simulations extensively used to define protection systems and to determine protection levels– Quantitative results requirements identified, specification of surveillance performance
– LHC “fully protected” with foreseen active and passive protection• Require Fast Current Change Monitor to measure 0.1% I, ~50s
reaction time• FCCM Development (M. Werner) looks promising even for fast
extraction septum• Appropriate interlocking system has been specified
– At present the protection systems cannot fully exclude TL damage• alternative solutions are being studied
• Simulations for total power cut and combined failures (protection device failure + other failure) will be carried out