1. + many slides from various colleagues (KH, Rudiger, Paul, …)
Introduction to electrical circuits terminology and machine sectorisation
M.Zerlauth, CO-MI
+ many slides from various colleagues (KH, Rudiger, Paul, …)

2. Outline Yesterdays presentation of KH Dangers in electrical circuits
Stored energies
Quenches
Components of electrical circuits
Machine sectorisation and naming conventions
Basics
Electrical Circuits
The concept of Powering Subsectors
Electrical Circuit terminology and concepts
Naming conventions
Electrical Circuit components
Circuit Types
LHC Layout Database 2

3. Machine Sectorisation and
naming conventions

4. LHC Powering in 8 Sectors
For superconducting magnets, no DC powering across IPs
Commissioning possible for each sector, independent of other sectors
Main DC power feed at even points (MB, MQ)
Some DC power feed at odd points
Total of 1716 electrical circuits with > sc and nc magnets in LHC 5 4 6
DC Power feed
Octant 3
DC Power 7
arc cryostat
LHC Sector 2 8
Sector 1
P.Proudlock

5. Sector vs Octant vs electrical ‘half’-cells

6. The FODO Cell = 1 ‘electrical cell’

7. Corrector Magnet Circuits

8. Standard FODO cell = 2 electrical ‘half’-cell

9. Electrical half-cells - Electrical Circuits & connections
To be found on CDD:
LHC_LSD%
+ Layout Database
Line N
Main Busbars +
Spool-pieces

10. Circuits and DFBs

11. Naming Convention =f (position)
Examples:
MB.A10R1 = Magnet of type MB, first instance
in half-cell 10 right of point 1 (B1 & B2)
MCO.15R1.B1= Magnet of type MCO, only instance
in half-cell 15R1, acting on B1 only
Examples:
RB.A = Electrical Circuit connecting all magnets
of type MB in the arc 78
RQS.L8B1 = Electrical circuit connecting a magnet/
magnets, left of 8 and acting on Beam 1
LHC Home – Naming Conventions:

12. LHC Layout DB:

13. Sectorisation across systems
Different sectorisation chosen by different systems, as the machine can be seen from different angles (mechanical, beam physics, electrical powering, cryogenics, vacuum…)
Most important configuration for magnet powering (and current HWC) is the POWERING SUBSECTOR
LHC-D-ES-0002 v.1.0

14. Concept of Powering Subsectors
8 machine sectors are sub-divided into
28 powering subsectors
8 arc subsectors (A12, A23, … A78, A81)
8 triplets (XL1, XR1, XL2,…, XR8)
12 matching sections (LL1, ML2, MR2, …MR8)
Powering Subsector are electrically isolated from each
other
Main motivation is independent powering

15. Cyostats in sector 7-8 Y.Muttoni IP7 UJ76 SD7 TZ76 RR77 RE78 RE82 RA83
Point 7
Ferney
RE78
RE82
PM76
RA83
UJ83
UA83
5 cryostats
- Q6 (DFBMH)
A78 (DFBAN - DFBAO)
Q5 (DFBMC)
- Q4 /D2 (DFBMA)
- XL8 (DFBXG)
Point 8
Prevessin
IP8
Y.Muttoni

16. Sector 7-8 and cryostats IR7 Insertion Cleaning IR8 Insertion LHCb
Matching
section
Arc cryostat (3 km)
Matching
section
Inner
Triplet
DFBMH
DFBAN
DFBAO
DFBMC
DFBMA
DFBX
Each cryostat has its own set of PC. Only the beam, the access, the vaccuum, and the cryogenics couple
Each cryostat one PPC (arc needs two, because fed from both sides)
PPC close to the PC
view from inside LHC ring

17. Quadrupole Correctors
Sector 7-8 and magnets
IR7
Cleaning
Matching
section
Arc cryostat (3 km)
Matching
section
Inner
Triplet
IR8
LHCb
DFBMH
DFBAN
DFBAO
DFBMC
DFBMA
DFBX
Quadrupole Correctors
154 Arc dipole magnets and correctors
Short straight sections (Quadrupoles and correctors)
Quadrupole Correctors
Insertion dipoles
IR Quadrupoles
Correctors
Each cryostat has its own set of PC. Only the beam, the access, the vaccuum, and the cryogenics couple
Each cryostat one PPC (arc needs two, because fed from both sides)
PPC close to the PC

18. Sector 7-8 and underground areas
IR7
Cleaning
Matching
section
Arc cryostat
Matching
section
Inner
Triplet
IR8
LHCb
DFBMH
DFBAN
DFBAO
DFBMC
DFBMA
DFBX
Each cryostat has its own set of PC. Only the beam, the access, the vaccuum, and the cryogenics couple
Each cryostat one PPC (arc needs two, because fed from both sides)
PPC close to the PC
UJ76
RR77
UA83

19. Sector 7-8 and power converters
IR7
Cleaning
Matching
section
Arc cryostat
Matching
section
Inner
Triplet
IR8
LHCb
DFBMH
DFBAN
DFBAO
DFBMC
DFBMA
DFBX
Energy extraction
Each cryostat has its own set of PC. Only the beam, the access, the vaccuum, and the cryogenics couple
Each cryostat one PPC (arc needs two, because fed from both sides)
PPC close to the PC
UJ76
RR77
UA83
Power Converters
and other equipment
Power Converters
and other equipment

20. Sector 7-8 and powering subsectors
IR7
Cleaning
Matching
section
Arc cryostat
Matching
section
Inner
Triplet
IR8
LHCb
DFBMH
DFBAN
DFBAO
DFBMC
DFBMA
DFBX
Each cryostat has its own set of PC. Only the beam, the access, the vaccuum, and the cryogenics couple
Each cryostat one PPC (arc needs two, because fed from both sides)
PPC close to the PC
UJ76
RR77
UA83
Powering Subsector
A78
34 electrical circuits
Powering Subsector
A78
43 electrical circuits
Powering Subsector
ML8
15 electrical circuits
Powering Subsector
XL8
14 electrical circuits
Powering Subsectors: LHC-D-ES-0002 EDMS Document No

21. Electrical Circuits and
Terminology

22. Normal-conducting circuits
40 nc circuits in the LHC, connecting some 144 magnets
RD1.LR1, RD1.LR5
RQ4.LR3/7, RQ5.LR7, RCBWH/V in IR 3/7
RMSD in IR6…
Mainly in cleaning insertions (IR3, IR7) and close to high luminosity experiments
8 additional powering subsectors ‘WLR1’, ‘WLR2’,…
Warm Magnet
Interlock Controller
Power Converter
Normal conducting
cables
Several thermo-switches
@ 60°C
Magnet 1
Magnet 2

23. Superconducting magnets / circuits
98% of circuits in the LHC are superconducting
~1680 circuits, connecting > magnets
Various families f (energy, current, # magnets, location, …)
Rated current range from 60A – 13kA
Normal conducting
cables
Power Converter
Superconducting
Diode
Energy Extraction
Quench-
Heater
QPS
HTS
Current Leads
Quench Signal
Magnet 1
Magnet 2
sc busbar
DFB

24. Power converters and water cooled cables
Water cooled cables 12 kA
Power converter 6 kA

25. DFBs with current leads - feeding current from warm to cold
DFB and current leads

26. Cryogenic Feed Box with HTc Current Leads

27. Cryogenic Connection

28. Installation of the Cryogenic Transfer Line

29. (13kA for 8RB, 24 RQD/F circuits) 202 DQEMC systems (600A circuits)
Energy extraction resistors MB
Energy extraction switch house 12 kA
32 DQR/DQS systems
(13kA for 8RB, 24 RQD/F circuits)
202 DQEMC systems
(600A circuits)
Energy extraction switch 12 kA
Diode for 12 kA

30. The LHC Magnet Zoo

31. Superconducting Magnet Units
Not quite up to date…

32. Magnet inventory
1232 main dipole magnets powered in series with the same strength
to make it around the LHC
752 orbit corrector magnets powered individually
to ensure that the beam follows the design orbit (within about 0.5 mm),
Focusing and defocusing quadrupole magnets powered in series
to keep beam size limited
Lattice sextupole magnets powered in series
to correct the trajectories for off-energy particles,
Multipole-corrector magnets (sextupoles, decapoles, octupoles, ...)
to correct field imperfections, to suppress instabilities, etc., powered in series
Corrector magnets to adjust essential beam parameters (quadrupoles)
Insertion dipole and quadrupole magnets
to ensure beam crossing / increase the interbeam distance / focus beams for experiments etc. 32

33. Circuit Types defined for HWC and operation
60A (752 orbit corrector circuits)
80-120A (LSS and DS orbit correctors)
600A EE (600A correctors with Energy Extraction System)
600A no EE (600A correctors without Energy Extraction)
600A no EE crowbar (600A correctors without EE, but additional crowbar)
IPQ (Individually powered quads, Q4-Q10)
IPD (Separation and re-combination dipoles)
IT (Main Inner Triplet Circuits)
Main Dipole and Quadrupoles

34. QPS Types QPS classification as function of
# magnets in circuit (stored energy)
Extraction system
Parallel protection (diode or resistor)
Quench heaters

35. PC_DISCHARGE_REQUEST
Interlock Types
PC_PERMIT
QPS
PIC PC
Interlock Type A
(=13kA main + IT)
PC_FAST_ABORT
CIRCUIT_QUENCH
POWERING_FAILURE
DISCHARGE_REQUEST
PC_DISCHARGE_REQUEST
PC_PERMIT_B1 PC
QPS
PIC
PC_PERMIT_B2 PC
Interlock Type B2
(=all quads of IPQ)
PC_FAST_ABORT
CIRCUIT_QUENCH
POWERING_FAILURE
PC_PERMIT
QPS
PIC PC
Interlock Type B1
(=600A EE, 600A no EE, 600A no EE crowbar + all dipoles of IPD)
PC_FAST_ABORT
CIRCUIT_QUENCH
POWERING_FAILURE
PC_PERMIT
PIC PC
Interlock Type C
(= A)
POWERING_FAILURE

36. Types of electrical circuits
A: main dipoles (8), main quadrupoles (16), triplet quadrupoles (8)
extraction of the energy stored in the magnets when requested by the Power Converter in case of failure is performed by the QPS
B: magnets equipped with QPS
B2: insertion quadrupoles using MQM / MQY (3.9kA – 5.8kA)
B1: insertion dipoles (4.6kA-6.2kA) and most 600A corrector magnets
extraction of the energy stored in the magnets not required in case of Power Converter failure
B1: electrical circuits with one Power Converter
B2: electrical circuits with two Power Converters
C: dipole corrector magnets in the insertions and other circuits with corrector magnets with little stored energy (60A, 80A and 120A)
connection to Powering Interlock Controller
D: orbit dipole corrector magnets in the arcs (60A)
no connection to Powering Interlock Controller

37. Physical installations in RR77
Powering
Interlock
System
QPS 600A protection unit
600A EE system
600A converter

38. Physical installations in RR77
Patch Panels
Industrial Controller

39. Conditions for powering
Cryogenics: Magnet and current leads must be at correct temperature
Safety systems: must be ready (AUG – arret urgence general, UPS – uninterruptible power supplies, …)
Power converter: must be ready (including cooling water etc.)
Quench protection system: must be ready (quench heaters charged, extraction switch closed)
Power converters
Operator / Controls: must give permission to power
Powering Interlock Controller (PIC)
Energy extraction
Warming up of the magnet due to failure in the cryogenic system
Warming up of the magnet due to quench in an adjacent magnet
AUG or UPS fault
Power converter failure
Quench in a magnet inside the electrical circuit

40. Layout DB
All this can also be found and browsed in detail in the LHC Layout DB: 40

41. Thanks a lot for your attention
Questions? 41