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LER Magnets Major R&D Effort. There are 2 distinct sets of magnets: Arc magnets covering ~ 26 km of accelerator circumference LER to LHC transfer line magnets covering total of ~ 1 km of beam path The VLHC low field magnet is proposed - PowerPoint PPT Presentation
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April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER Magnets Major R&D Effort
The new injection scheme shows only the path from SPS to LER to LHC
There are 2 distinct sets of magnets:
1. Arc magnets covering ~ 26 km of accelerator circumference
2. LER to LHC transfer line magnets covering total of ~ 1 km of beam path
The VLHC low field magnet is proposedas the base magnet for the LER arc.
The LER-LHC transfer line magnets areviewed as new initiative in magnet design.
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
VLHC & LER Magnet Count
FNAL
Fermilab cluster:Injection, Extraction,RF, Two Detectors
Typical Stage 1Surface Facility forCryogenics (1 of 6)
Far ClusterLF -> HF Transfer
and Collimation Ring OrientationArbitrary
Stage 1
Required for Stage 2
VLHC: - 233 km accelerator ring - ~ 3200 main arc dipoles - ~ 466 km continued length of transmission line superconductor
LER: - ~27 km accelerator ring - 1232 main arc dipoles - ~ 54 km continued length of transmission line superconductor
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Base Magnet of the LER Accelerator
LER Main Arc Dipole Magnet • Magnet cross-section area: 26 cm (height) x 24 cm (width) Pole gap: 20 mm (?)• 1.6 Tesla field (nominal operation) (1.99 T for VLHC)• 0.6 Tesla (beam injection) (0.2 T for VLHC)• Alternating gradient: 12 m (64 m)• 20 mm magnet pole gap ( 25 mm ??)• Energized by 55 kA (87 kA for VLHC), single turn superconductor line• Coolant – supercritical helium (4.2 K, 3 bar, 60 g/s) • Warm beam pipe vacuum system- ante-chambers required
We propose that LER is based on theVLHC low field, combined function dipole magnet
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER Magnet Location in the LHC Tunnel
It fits easily in the space above the LHC magnet
-Vertical distance between LHC and LER beams: 1350 mm
-The holding brackets and the magnets can be installed without disturbing the LHC operations
-The 4 K, 3 bar LHe can be tapped at convenient locations from the QRL line providing 1700 g/s flow
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER Arc Dipole Magnet in LHC Tunnel
Normal tunnel area Area with cryogenic feed tower
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
VLHC Magnet and B-field Measuring Instrumentation
Magnet view (tangential coil side) Magnet view (Hall station side)
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Magnetic Measurements
Gueorgui Velev, TUA07PO02
Probe: 15.2 mm dia. x 754.1 mm longVespel (polyimide) used to form the probe (winding support) and bearings.
Field Harmonics measured to:order 10 at 1.966 Tesla (collisions),and order 6 at 0.1 Tesla (injection)
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Magnetic Measurements
Quadrupole component is as designed; ~ -415 units, both atinjection and full field 1.966 T.
102 element Hall Probe confirmsthe +/- 4% gradient.
Sextupole component very small;~ few units, and no change frominjection to the full field 1.966 T.
The b4 – b10, and the a4 – a10 also << 4 units, or << 0.04%.
LER magnet operates at 1.6 T !!
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Principle of the LER-LHC Beam Transfer
After the LER ring filling is complete, the pulsing magnets are turned off as soon as the last proton bunch passed through them.
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Principle of LER-LHC beam transfer
Cryogenic support for fast pulsing magnets must sustain long-termoperations at 0.45 TeV, and a 100 second long ramping to 1.5 TeV
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER-LHC Transfer Line Boundaries
- Total length of ½ straight section: 260 m- Available free space between D1 and Q7: 176.5 m - To reproduce the LHC optics the LER-LHC transfer line magnets must reach the LER
level of 1100 mm at the D2 LHC dipole (approximately 65 m from the end-face of D1)- A 336 T-m bending power is required to lift a 1.5 TeV beam by 1100 mm above the
LHC nominal beam level, or on average ~5 T magnets are required for a 65 m beam path
- For comparison, to bypass detectors by ~ 40 m in the straight sections of 260 m the transfer line magnets of ~50 T field would be needed
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER-LHC Transfer Line Option 1No re-arrangementof LHC, D1 magnet.
4 vertical bendspreceded by a horizontal bend toprovide enough separation in thefirst pair of vertical dipole magnets forthe “cc” and “cw” LER beams.
Three sets of fast pulsing magnets
are needed!
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER-LHC Transfer Line Option 2
LHC D1 magnet ismoved a bit (or shortened) to make a space for a (5
m?) LER single bore dipole magnet.
Only one set of fastPulsing magnets isneeded!
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
An Example of Possible Vertical Bend Magnet Arrangement
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER-LHC Transfer Line Magnets
In order to accomplish the LER-LHC beam transfer the beam line must consists primarily of three type of dipole magnets:
- 2 T range, normal conducting, fast pulsing, single bore dipole to
enforce the LER beam circulation in the LHC
- 2 T range, normal conducting, single bore dipole operating with
the LHC LER beam pipe separation of no less than 75 mm (40 mm beam pipe and ~ 30 mm for the magnet yoke)
- 7-8 T, superconducting, two-bore, 1m long vertical dipole to pass
the LER beam through most of the 1.35 m vertical separation
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Fast Pulsing Magnets
- For 3 microseconds current decay time, L < 1 uH, so the magnet length is typically < 1 m, and the conductor spacing 40-60 mm.- For B field in 2 T range, the conductor current is in the range of 100 kA.- Magnet operating < 25 K (lowest resistance of Cu) is the only option.
From Martin N. Wilson,Superconducting Magnets,ISBN 0 19 854810 9 (Pbk), 1997
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Fast Pulsing LER-LHC Transfer Line Magnets
Horizontal bend of both LER beams. Vertical bend of the LER beams,B-field shaped by laminations, B-field shaped by conductors,conductors are LHe cooled. conductors are LHe cooled.
40 mm gap, 1.5 T max @ 90 kAPulsed or continual operation
60 mm gap, 2.0 T max @ 67 kA pulsed or continual operation. CERN operated WC 0.6 T magnet @ 29 kA
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER-LHC Transfer Line Magnets
A vertically bending magnet –for horizontally separated LERand LHC beams.
Continual or fast pulsing operations.
Laminations are used to contain
magnetic flux, and to minimize fringe field at the LHC beam.
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
Fast Pulsing Magnet Power Supply
For I = 90 kA and L =1 uH of the magnet system, the voltage drop is 30 kV at
3 microsecond of current decay time. Lowering the operating temperature of the power supply switcher cells to 25 K will eliminate need for the HTS leads.
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER Major Magnet R&D for FY07
1. Dipole, 2T range, single bore (30-50 mm), 0.8 m long, dc, 3 microsecond turn-off time, LHe cooled condcutors: (a) magnetic field shaped by conductor (b) magnetic field shaped by Silicon Steel tape core
Goal for FY07: magnetic and mechanical/cryo design
2. A 100 kA dc power supply with 3 microsecond turn-off time: (a) switcher cells operating below 100 K, possibly down to 25 K (b) fast transformer/heater to turn-off the current (c) superconducting dump resistor to expend
magnetic energy
Goal for FY07: research and preliminary design
April 27, 2006 LARP LBL Meeting Henryk Piekarz
SC Magnetsat Fermilab
LER Major Magnet R&D for FY07
3. Two-bore (40 mm), high field (7-8 T) vertically bending magnet:
set of short (0.8m) 12-15 magnets arranged into a single cryostat
Goal for FY07: magnetic and mechanical/cryo design
4. VLHC combined function magnet, 1.6 T, 25 and 30 mm gaps:
Goal for FY07: magnetic design