Cryogenics for crab cavities SPS/LHC 2 nd HiLumi LHC meeting Frascati (Italy) 15 November 2012 K. Brodzinski and L. Tavian on behalf of cryogenic team

K. Brodzinski - HiLumi LHC, Frascati 2012 1

Cryogenics for crab cavities – SPS/LHC

2nd HiLumi LHC meeting – Frascati (Italy) 15 November 2012

K. Brodzinski and L. Tavian on behalf of cryogenic team at CERN

K. Brodzinski - HiLumi LHC, Frascati 20122

Contents

• Baseline for the cavities testing – general assumptions

• SPS BA4 cryogenic infrastructure

• Existing cryogenics and required modifications

• Budget and planning

• LHC cryogenics at P4 and at Hi Lumi experiments (P1 & 5)

• Conclusions


Baseline for the testsCrab Cavity test will be performed at 2 K firstly at SPS ring then integrated on LHC.

(LHC is not considered as a test bench … -> that is why SPS test is required)

P4

- Test on SPS then LHC P4 ? - Planned final destination on LHC


Sulzer-Linde TCF20 in BA4

Nicolas Delruelle

At SPS BA4 there is a 4.5 K cryogenic infrastructure used last time about 8 years ago for COLDEX experiment. It is foreseen to test its capacity and upgrade it for 2 K refrigeration – refurbishment is underway

TCF20 – and required upgradeExisting 4.5 K cryogenics

Coupler heatintercept

Subcooling HX

VLP heater (~2 kW)

He guard

Warmpumping unit

(1 g/s @ 15 mbar 1500 m3/h)

JT valve

VLP line

5

TU1

TU2

JT

HPLP

TCF20

CC

TU1

TU2

JT

HPLP

TCF20

CC

Cryolines

Thermal shield

Pressure relief valves

War

m re

cove

ry li

ne

Required 2 K cryogenics

All parts marked in red have to be developed, integrated, installed and commissioned.

Service module

Crab cavity cryostat

COLDEX



Crab-cavity test in SPSAdditional specific 2 K equipments

Warm pumping unit to be integrated in BA4 !(new or recovered from AMS – needs service)

Subcooling heat exchanger and JT valve to be integrated in dedicated service module.


Crab-cavity test in SPS – limitations Crab cavity cooling at 2 K TCF20 cryoplant used in pure liquefactionTCF20 means 20 l/h = 0.7 g/s of LHe

Estimated thermal loads:• Coupler heat intercepts: 2 W => ~0.1 g/s of liquefaction• Dynamic RF load at 2 K: ~12 W => ~0.57 g/s of liquefaction• Static heat inleaks (service module, cryostat, transfer lines): ?

TCF2

0 T-

S Di

agra

m

Guaranteed capacity: 87.5 W @ 4.5 K(i.e. isentropic equivalent to ~0.85 g/s of liquefaction)

K. Brodzinski - HiLumi LHC, Frascati 2012 8

Measured TCF20 refrigeration capacity

120 W available in refrigeration mode ! (+ 35 %)

Giorgio Passardi


Crab-cavity test in SPSTCF20 capacity limitation

Conclusions:• Liquefaction capacity measurement mandatory to confirm possibility of cooling @ 2 K• Only one cavity can be tested with existing cryo plant (above loads are given for one

cavity)• Realistic specification needed !

Dynamic heat loadold ass. (12 W)

new ass. (2.5 W)(5 W per module)

Coupler intercepts(2 W)(2 W)

(4 W per module)

Static heat load(4 W ?)(4 W ?)

(5 W per SM + cryostat)

Could be a difficult limit

0.7 0.85 1.2Liquefaction capacity line [g/s]

10

Crab-cavity test in SPSAdditional specific 2 K equipment

• Refurbishment of existing equipment (4.5 K) 150 kCHF • Sub cooling heat exchanger 12 kCHF• Warm pumping unit (WPU) 100 kCHF• He guard for pressure relief valves 10 kCHF• VLP heater 20 kCHF• JT expansion valve 4 kCHF• Service Module + piping 50 kCHF

• Total ~350 kCHF

Remarks: 1. some additional cost for cryostat design can occurred e.g. beam screen circuit2. if WPU cannot be installed underground, a new VLP line must beintegrated in the BA4 shaft (DN100 – 20 kCHF)3. No specific purifier foreseen for impurity management of the VLP circuit, i.e. availability affected in case of 2 K refrigeration.


Tentative SPS CC cryogenic schedule


• Surface equipment (GHe storage, compressor station and oil separation system)

– refurbishment completed (run test to be done by end of 2012)

• Cold box refurbishment is underway – run test on the beginning of LS1

• Installation of liquefaction test instrumentation and test performance –

by 15 June 2013 (cut of cooling water in SPS BA4 until ~ 15 September 2013).

• Development, installation and commissioning of 2 K equipment by end of LS1

Remark:Integration of 2 K cryo equipment in the tunnel looks tight – if not possible heavy complications – possibility of mentioned transfer line construction in the shaft to the surface = more logistics, more manpower and time required.


Crab cavity test at Point 4• The global scheme is no longer an option for the final HL-LHC, but a prototype

cavity could be installed in Point 4 after the tests in SPS.

• Installation of CC prototype could be:– Coupled to the RF cryogenic upgrade at P4 with 2 K equipment to be added– Scheduled during the LS2 (2018) for possible validation tests during 2019/20/21

(before the LS3 for P1/5 upgrade).

• Equipment for 2 K refrigeration – a new pumping system must be added:– Additional cooling capacity: ~26 – 30 W @ 2 K per CC module, i.e. 52 – 60 W in total– Warm vs cold pumping:

• Pumping capacity: ~ 3 g/s Warm pumping probably more dedicated• Warm pumping OK for no continuous test (i.e. during MD period) but lower system availability

for continuous operation– Extra cost: ~0.5-1 MCHF depending impurity management– Amplified space – tight integration

13

Project Process & flow diagramwithout crab-cavities (4.5 K)

Gérard Ferlin


surfa

cesh

aftca

vern

and

tunn

el


P4 upgrade for RF cooling

First studies to install a cold box, 6.5 kW @ 4.5 K into UX45 cavern, above RF electrical cabinet

Gérard Ferlin et al


SPS and P4 CC tests – scheduleTentative planning of P4 cryogenics upgrade and CC integration

Remarks/remind:• If CC are going to P4 they can be connected with new RF refrigerator but its

infrastructure will be operational only during LS2 ( 2 K part to be added)• Second option is to feed CC at P4 from existing cryo distribution (2 K infrastructure

to be integrated). Clear decision about CC test at P4 is required to study corresponding requirements with related planning.


Crab cavities for the final local scheme

• Configuration: 2 modules per beam, i.e. 4 per Interaction Points (IP1 & IP5)

• Installation: during the LS2/3 (2018 – 2022) dedicated to the last phase of HL-LHC project

• Cooling capacity requirements:– 2 K cooling: ~26-30 W per CC module (i.e. 104-120 W per IP)

• Energy consumption consideration:– COP @ 2.0 K refrigeration: ~800-1000 W/W, i.e. a consumption of 21-30 kW of electrical

power per CC module


Cooling of CC modules at P1 and 5• Two possibilities:

– Via the 2 new cryoplants dedicated to the new inner triplets at IP1 and IP5 or– Via the 4 existing adjacent-sector cryoplants

• The choice will depend strongly on:– the operating temperature of the new Inner Triplets (IT): 4.5 K vs 2 K– the total added heat loads

Remarks:• It is probably preferable to link the CC with new refrigerators for ITs, if not we will recreate

currently existing in s3-4 and 4-5 unbalance which has justified upgrade of cryo at P4 • Studied schemes of cryogenic upgrade for HL-LHC at P1 and 5 will be presented on Friday

16.11.2012 at 10h00 “Cryogenics for HL-LHC” by Laurent Tavian.

Existing Cryo plants

New Cryo plant for RFs New Cryo plant for ITs and … CC

Sector 3-4 Sector 4-5 Sector 5-6LHC RFs


Conclusions• Prototype crab-cavity testing in SPS:– Test possible from end 2014.– Refrigeration at 2 K:

• liquefaction capacity of the TCF20 must be measured and sufficient.• Additional resources (P + M) must be allocated.

– Additional 2 K infrastructure to be built – could be in conflict with the LS1 activities – tight to be integrated.

• Prototype crab-cavity testing at LHC P4:– Test possible from 2018/2019 ... or before using TCF20 from SPS BA4– 2 K cooling (~1 MCHF + 2 FTE + a possible noise-insulated building tension/construction…?).

• Series crab-cavities for the final HL-LHC local scheme:– Cryogenic implementation during the LHC LS3 (2022)– 2 K cooling via new ITs cryoplants preferable:

• Option for Matching Section area to be cooled by the same cryoplant• Cooling with existing sectors cryo plants not excluded but with load unbalance wrto the other LHC sectors

• Crab cavity prototype and cryostat study dedicated meeting will be held in FermiLab on 13-14 December 2012 (key decisions to be taken)

Documents

Cryogenics for crab cavities SPS/LHC 2 nd HiLumi LHC meeting Frascati (Italy) 15 November 2012 K. Brodzinski and L. Tavian on behalf of cryogenic team