Transcript 20160321D1_NakamotoFinalx

D1 Protection
Aspects and
Instrumentation
T. Nakamoto
KEK
The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European
Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
Design Parameters of MBXF for D1
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Coil ID:
150 mm
Integrated field:35 T m (26 Tm at present LHC)
– 5.59 T at 12 kA. Lcoil=6.6 m
• Top:
1.9 K by HeII cooling
• Op. point (2D coil):
75 %
• Coil layout:
1 layer of 15.1 mm cable
– Better cooling. Saving space for iron yoke.
• Conductor:
Nb-Ti LHC MB outer cable
• Structure:
Collared yoke structure by keying
• Field quality: < 10-4 at Rref = 50 mm
• Cold mass OD: 550 +10 x 2 = 570 mm
• Cryostat OD: 914 mm, same as MB cryostat (*TBD)
• Radiation, energy deposition:
135 W in total, 2 mW/cm3 at local peak, Radiation dose >25 MGy
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8
13
44 turns
2016/03/21
Conceptual Design Review of the Magnet
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2
2m-long Model Magnet - Overview
Single-layer coil, 4-split spacer collars, collared yoke by keying
Notches and f 34 mm f60 mm HX hole
holes for iron saturation
effects
HeII cooling channel
Shell: SUS304L
4 split stainless steel
spacer collars:
NSSC130S
Brass shoes
QPH+Insulations
Collaring keys
NbTi SC cable (LHC MB
outer) + Apical insulation
Radiation resistant GFRP (S2 glass + BT resin) wedges
2016/03/21
Conceptual Design Review of the Magnet
Circuits for the HL-LHC
Horizontal split iron yoke:
low-carbon steel (EFE by JFE steel)
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Parameters
2m Model
General
Field integral
Coil aperture
Nominal dipole field
Coil peak field
Load-line ratio
9.8 T·m
Operation temperature
Magnetic length
Stored energy
Differential Inductance
Number of turns in quadrant
Superconducting Cable
Superconductor
Cable type
Strand diameter
Coating
Copper to SC ratio
Filament diameter
Number of filament
RRR
Critical current (9 T, 1.9 K)
Number of strand
Cable bare width & mid-thickness
Insulation 1st & 2nd layer
3rd layer
35 T·m
150 mm
5.57 T
6.44 T at center, 6.59 T at coil end
75.4 % at center, 76.6 % at coil end
Nominal & ultimate current
2016/03/21
Production Magnet
12.0 kA & 13.0 kA (~108% nominal)
1.9 K
1.73 m
6.27 m
340 kJ/m
4.0 mH/m
44 (4+8+13+19) turns in a single layer coil
Nb-Ti
LHC MB outer cable
0.825 mm
Sn5wt%Ag
1.95
6 mm
6500
> 150
> 380 A
36
15.1 mm & 1.480 mm
APICAL (0.05 mm thick, 11 mm wide), 1/2
overwrap
Conceptual Design Review
of the(0.069
Magnetmm thick, 9 mm wide), adhesive,
PIXEO
Circuits for the HL-LHC
2 mm gap wrap
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2m Model Development
1st cold test at KEK in April and May 2016.
2016/03/21
Conceptual Design Review of the Magnet Circuits for the HL-LHC
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A Bit of History
• Initial concept of the quench protection for the D1 magnet was “a 75 mW
dump resistor w/o heaters”, until May 2015.
– Max. MIITs at 108% nominal current is estimated to be 40 and a hot spot
temperature is around 300 K. It looked OK.
• After C&S Review in March 2015, the baseline was changed to “protection by
heaters w/o a dump resistor”.
• In July 2015, a tentative heater design was adopted for the 1st model based
on the experience of MQXA.
– KEK cannot find the heater manufacturer in Japan. CERN provided the
heaters for the 1st model magnet.
2016/03/21
Conceptual Design Review of the Magnet
Circuits for the HL-LHC
6
Protection Heaters in the 1st 2m Model
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1 heater strip (SS, t0.025mm, w15mm, covered by 0.05 mm
thick polyimide + glue) covers 9 turns of the lower field coil
block in a quadrant coil. Copper plate only at ends for joints.
– 4 heater strips in the magnet.
2 strips in series are connected to a standard LHC heater
power supply (900V, 7.02mF). 2 heater circuits in the magnet.
QPHs for the 1st 2 m model have been delivered from CERN
– Thanks to Juan Carlos Perez and Francois-Olivier Pincot
QPH leads were soldered with “omega”.
The detailed analysis is ongoing.
PS 1
PS2
PS2
PS1
2016/03/21
Conceptual Design Review of the Magnet
Circuits for the HL-LHC
Omega
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Spot Heaters & V-taps of the 1st Model
Lead end
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10
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9
5
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29 28
4
8
17
27 26
Spot heater at
low field region
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– 29 voltage taps per coil
– 2 spot heaters in high
and low field regions
(20 V, 40 W)
Return end
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Spot heater at
high field region
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2016/03/21
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Conceptual Design Review of the Magnet
Circuits for the HL-LHC
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Heater Tests Planned for the 1st 2m Model
(TBD)
• Test currents: from ~500A (Injection) to 12000A (Collision).
– Some tests at +12000A (Ultimate current at training
campaign in the LHC machine) ??
• All hearer tests w/ a dump resistor of 75 mW, except for the full
energy dump test.
• Spot heater test: SHs located at lower and higher field will
induce the quench (see previous slide). Quench velocities and
detection time for a given Vth will be measured by voltage taps.
• Protection heater test: Delay time. At different charge voltages
and energies.
• Full energy dump test (QPH w/o a dump resistor)
– 1 or 2 heater circuits
– MIITs
Conceptual Design Review of the Magnet
2016/03/21
Circuits for the HL-LHC
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Plan for Modification
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NP
Joint of top
and bottom
coils
Discussion already started with the circuit/protection group at
CERN (Auchmann, Wollmann).
Current proposal of design change from CERN
– To add a heater strips at high field in one quadrant coil.
>> 8 heater strips in the magnet.
• Not in the 1st model. Probably applied to the 2nd model.
• Concern is that the end saddle length should be
extended to prepare the groove for the omega joint.
>> increase of a mechanical length.
– Extension of SC lead at mid-point for possible
Vtaps
implementation of CLIQ in future.
for Q.D.
• Already prepared in the 1st model.
• Note: For CLIQ, max. voltage in the system will be
Additional heaters
increased to 450V (QPH P.S.) to 700V or more.
• Note: the 1st model will be shipped to CERN in 2016 for
further tests.
Difficult to put Q.D. v-taps for asymmetric quench in the D1.
SC lead
extension
for CLIQ
(~1m)
Additional groove
2016/03/21
Present groove
Conceptual Design Review of the Magnet
Circuits for the HL-LHC
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