ColUSM #51 30 th January, 2015 D. Duarte Ramos, C. Mucher, L.
Gentini, T. Sahner, H. Prin, R. Wawrowski, Q. Deliege, V. Baglin,
F. Savary
Slide 2
Click here to add footer 2 Outline Specifications, constraints
and goals As-installed magnet length Continuity of cryogenics and
powering (how did we got to the current layout) Beam vacuum
components and achievable collimator length Conclusion and comments
on eventual specification changes
Slide 3
Click here to add footer 3 Specifications, constraints and
goals Compatibility with installation and transport constraints:
not larger than existing cryostat (1055 mm) Create a room
temperature vacuum sector in the LHC continuous cryostat Cold to
warm transitions (CWT) Sector valve after each CWT for vacuum
separation during magnet cooldown or collimator bakeout. RF-
shielded gate valves and bellows for impedance reasons DN35 ports
on the cold sectors to send an RF emitter ball through the full arc
after warm up and before cooldown Compatibility with existing
cryogenic and electrical systems, ensuring their continuity Prevent
loss of alignment during evacuation with independent supports for
collimator and cryostat Minimise changes to other magnets: keep
interconnects standard if possible Collimator Vacuum enclosure
Magnet 1.8K Heat exchanger Beam vacuum Lines E, C, K RF emitter Bus
bars
Slide 4
Click here to add footer 4 Layout options (January 2013) New
end covers may be made to route the bus bars in a way to provide
enough space for the collimator. The price is loss of
interchangeability betwen cold masses Retained Additional module
needed to create a standard interconnect interface and thermal
compensation. Interference with W sleeve. Not possible to fit the
collimator nor sector valves between standard bus bar lines. New
routing needed to make vertical space for the collimator
Slide 5
Click here to add footer 5 As installed magnet length i.e. ~3.1
m availabe for collimator, interconnects and remainder
equipment
Slide 6
Click here to add footer 6 1 st Concept (Dec 2013)
Independently cryostated and handled cold masses, linked through
two short transfer lines Transfer lines with expansion joints
mechanically decouple cryostats A and B Splice and piping
interfonnect in the tunnel, all other work prior to installation
Can use the existing TCLD collimator design with modified the
supports Collimator Lines M, E, N, K, C Reinforced jacks to
widstand vacuum forces Cold mass ACold mass B Line X Independently
supported collimator Busbar splice and interconnect done in the
tunnel Flexible S-shaped busbar stabiliser Busbar lyra
Slide 7
Click here to add footer 7 1 st Concept (Dec 2013) 800 mm
Collimator Compatible with the collimator design developed in 2010
(TCLD) Starting assumption: busbar bypass can be made in the shadow
of the beam screens and CWT
Slide 8
Click here to add footer 8 After long months of idea generation
and testing The busbar routing proved to be a major challenge! Six
busbars in one duct: how to route lyras, large bellows, space for
an extra interconnect at the exit of the CM External MQ busbars:
How to connect to the existing magnets, space for the interconnect
at the exit of the CM for line M3 Three separate ducts for each
pair of bus bars: better but length to accomodate the pipe bends
and interconnect length still an issue Busbar bypass can be made in
the shadow of the beam screens and CWT Can Not
Slide 9
Technology Department Present layout Current working design
Design proposal 2 nd Concept: 2 magnets in one cold mass QTC-like
short bypass module upstream of 11T Two-in-one cold masses imply
moving several magnets radially or using orbit correctors to
compensate for the fact that the cold mass is straight Still not
possible to route the busbars without taking more length than
required by the beam vacuum components Herv Prin, April 2014
Slide 10
Click here to add footer 10 May 2014: A new approach QRL side
K2 M2 V2 W Y M1 M3 E C V1 K1 X N
Slide 11
Click here to add footer 11 3 rd Concept (current baseline)
Same 15660 mm length between interconnect planes as an LHC MB
Connection cryostat between two 11 T magnets to integrate the
collimator LHC MB replaced by 3 cryostats + collimator, all
independently supported and aligned: Same interfaces at the
extremities: no changes to nearby magnets, standard interconnection
procedures & tooling
Slide 12
Click here to add footer 12 Connection cryostat for collimator
integration Collimator support jacks Cryostat support jacks Cold
mass enlarged to 750 on the collimator side Constant LHC arc outer
flange diameter: 1055 Flexible interconnects for alignment
independency and thermal contraction Interconnects usestandard
componentsand tooling despite thenew compact layout Busbar routing
is now in the shadow of the beam screens and CWT!
Slide 13
Click here to add footer 13 Cross section of the connection
cryostat and collimator Dedicated collimator design. One collimator
design fits both beam lines M2 W Y M1 M3 E C X N Collimator
supported directly on the concrete slab Larger cold mass extremity
to open up space for the collimator
Slide 14
Click here to add footer 14 Beam vacuum & Collimator length
(1) 600 mm Collimator Warm drift vacuum chamber Possibility of
getting extra 50 mm but the interconnects will not have the same
length: 2 vacuum vessel variants or 2 interc. sleeve variants
Transitions needed to allow installation of sector valves Very
tight integration
Slide 15
Click here to add footer 15 Beam vacuum & Collimator length
(2) Interconnects become longer because of the beamscreens Very
compact cold line because of the sector valve RF shielding
Transitions avoided because there are no sector valves on the other
beam lines Cold drift vacuum chamber 650 mm Collimator
Slide 16
Click here to add footer 16 Conclusion The present baseline
layout allows to connect busbars and cryogenic lines without impact
on the length of the collimator Beam vacuum, design for RF
impedance, minimised radiation to personnel and beam line
inspection with emitter ball impose a minimum length of beam line
components, thus defining the collimator length Detailed design
studies revealed the constraints imposed by the beam line without
collimator Both warm and cold versions of that line require
validate with physical mockups/prototypes (preparation starting the
coming weeks) Should the outcome be positive, the collimator active
length can be 650 mm.
Slide 17
Click here to add footer 17 More space for the collimator
implies compromising No ports for RF ball test: +130 mm (applies to
both versions) No beamscreen on line without collimator: +120 mm
(applies to cold version only) Ex. no RF ball ports + no beamscreen
+ no quick flange: +310 mm (applies to cold version only) No quick
flange on collimator: +60 mm (applies to both versions)
Slide 18
Slide 19
Click here to add footer 19 Current leads for the trim circuit
2x 300 A conduction cooled leads Only one location is possible
Integration and design to be started Gas cooled leads not possible
both for lack of space and cryogenics Conduction cooled leads:
about 3.6 W/kA to 1.9 K (c.f. A. Ballarino) Local solution:
applicable everywhere in the LHC RT copper cables towards power
converter Similar to a Dipole Corrector Feedthrough in the SSS
(EDMS 328999)
Slide 20
Click here to add footer 20 [email protected] Before the 11 T
magnet development: QTC (2010) Main drawback: extensive machine
layout changes to create space 4.0 m + 0.5 m interc. = 4.5 m
installation length
Slide 21
Click here to add footer 21 [email protected] Could the QTC
cryostat concept be extended? Can only be finished after
cryostating Dealing with welding distortions is a major issue
Distortions amplified with length Adjustment of cold supports posts
is required Complicated assembly procedure Longitudinal butt-welds
Cover closure w/ fillet welds New approach needed