1 / 21

LER Magnets Major R&D Effort

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

ryder
Download Presentation

LER Magnets Major R&D Effort

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 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 • as the base magnet for the LER arc. • The LER-LHC transfer line magnets are • viewed as new initiative in magnet design. The new injection scheme shows only the path from SPS to LER to LHC LARP LBL Meeting

  2. VLHC & LER Magnet Count 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 LARP LBL Meeting

  3. 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 the VLHC low field, combined function dipole magnet LARP LBL Meeting

  4. 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 LARP LBL Meeting

  5. LER Arc Dipole Magnet in LHC Tunnel Normal tunnel area Area with cryogenic feed tower LARP LBL Meeting

  6. VLHC Magnet and B-field Measuring Instrumentation • Magnet view (tangential coil side) Magnet view (Hall station side) LARP LBL Meeting

  7. Magnetic Measurements Gueorgui Velev, TUA07PO02 Probe: 15.2 mm dia. x 754.1 mm long Vespel (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) LARP LBL Meeting

  8. Magnetic Measurements • Quadrupole component is as designed; ~ -415 units, both at • injection and full field 1.966 T. • 102 element Hall Probe confirms • the +/- 4% gradient. • Sextupole component very small; • ~ few units, and no change from • injection 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 !! LARP LBL Meeting

  9. 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. LARP LBL Meeting

  10. Principle of LER-LHC beam transfer • Cryogenic support for fast pulsing magnets must sustain long-term • operations at 0.45 TeV, and a 100 second long ramping to 1.5 TeV LARP LBL Meeting

  11. 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 LARP LBL Meeting

  12. LER-LHC Transfer Line Option 1 • No re-arrangement • of LHC, D1 magnet. • 4 vertical bends • preceded by a • horizontal bend to • provide enough • separation in the • first pair of vertical • dipole magnets for • the “cc” and “cw” • LER beams. • Three sets of fast • pulsing magnets are • needed! LARP LBL Meeting

  13. LER-LHC Transfer Line Option 2 • LHC D1 magnet is • moved a bit (or • shortened) to make • a space for a (5 m?) • LER single bore • dipole magnet. • Only one set of fast • Pulsing magnets is • needed! LARP LBL Meeting

  14. An Example of Possible Vertical Bend Magnet Arrangement LARP LBL Meeting

  15. 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 LARP LBL Meeting

  16. Fast Pulsing Magnets From Martin N. Wilson, Superconducting Magnets, ISBN 0 19 854810 9 (Pbk), 1997 • - 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. LARP LBL Meeting

  17. 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 kA Pulsed 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 LARP LBL Meeting

  18. LER-LHC Transfer Line Magnets • A vertically bending magnet – • for horizontally separated LER • and LHC beams. • Continual or fast pulsing • operations. • Laminations are used to contain • magnetic flux, and to minimize • fringe field at the LHC beam. LARP LBL Meeting

  19. 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. LARP LBL Meeting

  20. LER Major Magnet R&D for FY07 • 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 LARP LBL Meeting

  21. 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 LARP LBL Meeting

More Related