The SPL Cryo-module

V.Parma, CERN, TE-MSC

MSC Technical Meeting, CERN 27th June 2013

Outline• Introduction to the SPL study• Goals of the SPL cryo-module• The SPL Cryo-module:

– General layout & schematic– Supporting system – Active cooled couplers and heat load estimates– Mock-up validation of the supporting system– Cryogenics and cryogens distribution

• Contributions and working structure• Cavities status and Infrastructure in SM18• Planning and CMI resources• Summary

The SPL study at CERN• Initially aimed at LHC luminosity up-grade (LP-SPL): now

stopped• Now R&D study for a 5 GeV multi MW power beam, the

HP-SPL• Major interest for non-LHC physics: Fixed Target/Neutrino

Factory (but also ISOLDEII/EURISOL)

Length: ~540 m

Ejec

tion

to

Euris

ol

High b cryomodules

12 x 8b=1

cavities

Medium b cryomodule

High b cryomodules

Ejec

tion

20 x 3b=0.65 cavities

5 x 8b=1 cavities

6 x 8b=1 cavities

TT6

toIS

OLD

E

Debunchers

To fi

xed

targ

et/μ

fact

ory

High b cryomodules

From

Lin

ac4

0 m0.16 GeV

110 m0.79 GeV

186 m1.4 GeV

~300 m2.5 GeV

HP-SPL beam characteristics

~500 m5 GeV

SPS

PS2

SPL

Linac4

PS

ISOLDE

Layout injector complex

The SPL study: a new orientation

New objective of the SPL study (after Chamonix 2010 + a first budget cut):

• Focus on R&D for key technologies for the high intensity proton source (HP SPL)

In particular:• Development, manufacture and test of high-gradient β=1, 5

cells, 704 MHz cavities• Development, manufacture and test of RF couplers• Testing of a string of 4 β=1 cavities in machine-type

configuration:

Need for a short cryomodule for testing purposes

Short cryo-module: Goal & MotivationGoal:• Design and construct a ½-lenght cryo-module for 4 β=1 cavities (as close

as possible to a machine-type cryomodule)

Motivation:• Test-bench for RF testing on a multi-cavity assembly driven by a single or

multiple RF source(s)• Enable RF testing of cavities in horizontal position, housed in machine-

type configuration (helium tanks with tuners, and powered by machine-type RF couplers)

• Validate by testing critical components like RF couplers, tuners, HOM couplers in their real operating environment

Cryo-module-related goals:• Learning of the critical assembly phases:

– preparation of a long string of cavities in clean room– alignment/assembly in the cryostat;

• Proof-of-concept of the innovative supporting of cavities via the RF couplers

• Explore cryogenic operation issues

β=1 cryo-module in the linac

From 8 to 4 cavities the Short Cryo-module

Short cryomodule: schematic layout

Connection to cryo distribution line

CW transition

RF coupler, bottom left sideCavity additional support

1.7% Slope (adjustable 0-2%)

Cryo fill line (Y), top left Technical Service Module

EndModule

Phase sep.

Inter-cavity supportNow suppressed

Now suppressed

System/Component/Activity Person(s) in charge Lab

Cavities/He vessel/tuner construction

O. CapatinaT. RenagliaF. PillonN. ValverdeI. AvilesG. Devanz

CERN, EN-MMECERN, EN-MMECERN, EN-MMECERN/ESSCERN/ESSCEA-Saclay

SRF, magnetic shielding, Clean-Room activities, RF test stations (SM18)

T. JungingerK. ShirmJ. ChambrillonO. Brunner

CERN, BE-RFCERN, BE-RFCERN, BE-RFCERN, BE-RF

RF Power Coupler E. Montesinos, G. Devanz

CERN, BE-RFCEA-Saclay

Vacuum systemsCavity Surface preparation

G. VandoniS.Calatroni & Co.

CERN, TE-VSCCERN, TE-VSC

Cryogenics (& cryo infrastructure SM18)O. PirotteR. Van WeelderenT. Koettig

CERN, TE-CRGCERN, TE-CRGCERN/ESS

Survey and alignment P. Bestman CERN, BE-ABP

Cryo-module conceptual design

R. BonomiP. CoelhoV. ParmaD. PerezA. Vande CraenW. Zak

CERN/ESSCERN/ESS formerCERN, TE-MSCCERN formerCERN, TE-MSCCERN/ESS

Cryo-module detailed design & Integration & Cryostat assembly tooling

P. DambreP. DuthilP. DuchesneS. RousselotD. Reynet

CNRS/IPNO-OrsayCNRS/IPNO-OrsayCNRS/IPNO-OrsayCNRS/IPNO-OrsayCNRS/IPNO-Orsay

Cryo-module Technical Coordination V. Parma CERN

SPL Cryo-module Team

SPL Cryomodule Workspace

https://espace.cern.ch/spl-cryomodule/default.aspx (managed by R.Bonomi)

Cryo-module design presented/discussed in about 15 workshops, reviews and seminarsfrom 2009 to date (all information available on Indico)

The French in-kind (Protocol K/1597/DG) for SPL

• CEA-Saclay:– Supply of 8 tuners (all supplied);– Supply of 4+1 He vessels, according to CERN drwgs (contract

placed)– RF tests of tuners (in progress)

• CNRS-IPNO (Orsay):– Detailed design of cryostat (in progress, to finish end 2013):

• Supply of vacuum vessel + ???…(155 kEuro envelope)• Provide fabrication drwgs file for all cryostat components

– Detailed design of cryostat assembly tooling (in progress, to finish end 2013):

• Supply of fabrication drwgs file (for build-to-print)

• CERN will have to procure:– Cryostat parts not supplied by CNRS– Assembly tooling (based on build-to-print drwgs)

• and assemble the CM (SMA18)

SPL Cryomodule exhibition (CERN, French in-kind meeting, June 2012)

RF Power Coupler

Bulk Niobium 5Cells cavity

Helium Tank

CEA’s tuner

Hom Coupler

Bi-phase helium tube

Magnetic shielding

Inter-cavity support

Bellows

Double walled tube

SS CF UHV DN100

(P.Coelho)

(P.Coelho)

Supporting system mock-up (SMI2)

R.Bonomi, P.Coelho (former), A.Vande Craen, M.Souchet, W.Zak

Supporting system mock-up (SMI2)

• Aims. Investigate:– Cavity position stability and alignment Now first

(good) results– Sensitivity of cavity adjustment– Thermo-mechanical position stability (LN2)– CD/WU transients – Thermal profiles (rescaling LHe LN2) on coupler– Active control of T on coupler– Optical Wire Position Monitor

Supporting system mock-up (SMI2)

Optical Wire Position Monitor (OWPM)

Cavity position monitoring specs: • Static position or slow movements: absolute movements (x,y,z) of

each of 4 cavities during steady state operation and cool-down/warm-ups (300-2 K)

• Vertical range: 0-2mm• Precision: <0.05mm• Resolution : <0.01mm• Possibly vibration measures (0-1kHz)

Stretched wire Opto-coupler sensors

Last cavity support

This R&D can be useful to other applications for magnets

Photo-interrupter as displacement measurement devices:

R&D in progress

Typical RT response and linearity curves (TJ0006 sensor, 1 mm wire) (courtesy: J.C.Perez)

Multiple interrupters examples

First tests in LN2

SC CavitiesParameter Units Beta = 1 (nominal/ultimate)Cavity bath temperature [K] 2.0 Frequency [MHz] 704.4Accelerating gradient [MV/m] 25 Quality factor (x10^9), Qo 10/5 R/Q value 570 Cryogenic duty cycle [%] 4.11/8.22 Dynamic heat load p. cavity [W] 5.1/20.4

Nominal: 40 mA/0.4 ms beam pulse ; Ultimate: 20 mA/0.8 ms beam pulse.

Typical Qo-Eacc curveQoQR

accVPd

/

2

Power dissipation

Heat loads estimates

Note: Instrumentation not included

STATIC HEAT LOADS(1) RF off, DWT cool off(2) RF off, DWT cool onDYNAMIC HEAT LOADS(3) RF on, DWT cool on(4) RF on, DWT cool off

(R.Bonomi)

Helium vessel (CEA)

Tuners (CEA)

Cavities (BE-RF+EN-MME+TE-VSC)

Gate valves (TE-VSC)

Vacuum vessel (CNRS)

RF couplers (BE-RF)

Vapour cooled RF coupler for SPL

RF couplers with He gas cooled double walled tube

When RF is on, a distributed vapour cooling is essential to contain distributed RF heating (local heat intercepting can hardly provide efficient cooling)

Assembly sequence

1- String of cavities outside the clean room2- Mounting of the magnetic shields4- Mounting of the cryogenic distribution3- Mounting of the tuners and inter-cavity connections 5- Mounting of the coupler cooling line6- Mounting of the thermal shield7- Insertion in the vacuum vessel8- Closing the vacuum vessel

Design by CNRS-IPNO (S.Rousselot)

Assembly Tooling

Conceptual design in progress

2 parts vacuum vessel

• Material is low-carbon steel (LHC type)• Vessel as first Earth magnetic shielding for cavities• Flanges in St.steel (304L)• Procurement by IPNO starts end July 2013

Mechanical analysis at CNRS

Loads when closing

242mm

1.2mm rattrapé par 2 vis contigüesEffect of a gap at closure

CNRS-IPNO, P.Duchesne, P.Duthil

Cold magnetic shieldStatus:• Detailed design validated

Cold magnetic shield Double layer

Coupler side Tuner sideDesign by CNRS-IPNO (S.Rousselot)

Cavity vacuum valves

• Choice made with TE-VSC (G.Vandoni) valves purchased procured

Cryogenic Scheme Short Cryomodule

EE’ C

C2

XB

X YC3C1

LZ

Additional valves/level gauges to test feasibility of 2 K supply scheme

Cool down valves;tests should show if necessary

Cryogenic distribution

xy

z

Pumping line (XB)

To cold box

and SM18

2 phase tube(line X)

Vapours collectorLiquid container

LHe Level gauge

Courtesy CNRS-IPNO (S.Rousselot, P.Duthil)

Technical Service module: features

4.5 K vapor generatorreservoir (with elect.heater)

standard support

Last cavity IC support

Ph.Separator pot

DN80 gate valve (single valve)

CWT 50 K heat intercept

(views S.Rousselot, IPN-Orsay)

Cooling, Filling, level gauges filling line

X

Z

YY

Z

X

X

Z

Y

Filling line shifted from the cavity bath

INLET OUTLET

(views IPN-Orsay)

Valve box and cryogenic scheme in SM18

• Control valves grouped in a single valve box

• Valve box needed also for interfacing CM to cryogenic distribution in SM18

Valve boxStatus:• Conceptual design finished, (to be handed over to CRG for supply)• Valves being ordered by TE-CRG• Heater on the thermal shield will warm up thermal shield helium

to the CM needs (50K)

From SM18

To CM

Vacuum barrierVacuum vessel

Thermal shield

Courtesy CNRS-IPNO (S.Rousselot, P.Duthil)

Cryo-module instrumentation

~100 T gauges

10 Elec.heaters

4 He level gauges

4 Piezos, tuners,HOM

Pressure gaugesOptical Wire Position Monitor

- Choice to be finalised- pending procurement

Bunker integration studies at CERN

SM18 bunker

Valve box

RF distribution

Cryo line interface

Cryo-module

Study by P. Martinez Yanez and B.Riffaud, EN-MME

SPECIAL LENGTH CORRESPONDING TO CRYOMODULE ANGLE

Study by P. Martinez Yanez and B.Riffaud, EN-MME

Pending work (BE-RF+EN-MME):• Full integration study (access, services, safety evacuation of He, …)• Design and construction of an inclination table (0%-2%) for the cryomodule• Study the opening of the CM top part of vessel for in-situ maintenance and

construction of the handling equipment

Bunker integration studies at CERN

CRYOMODULE 2% INCLINATION

ISO 5 ISO 4

ISO 4 ISO

5

Top view of cleanroom upgrade

Needs:•Upgrade from ISO 7 to ISO 5•Add a new ISO 4 room for HPR operation•Create a external room for cleaning of small parts (flanges, screw...)•Add HPR and UPW production

Upgrade of SM18 clean-room

(J. Chambrillon CERN-BE-RF)

Niobium cavities-RI• 4 niobium cavities under fabrication at RI • Delivery dates: 1st cavity end of June, last cavity end of July• Status: Dumb-bells welded

I. Aviles & N. Valverde, EN-MME

Niobium cavity at CERN

Spinning of 2 half-cells and 1 beam tube at HEGGLI for testing

Dim

ensi

onal

con

trol

by

CMM

RF measurements.

I. Aviles & N. Valverde, EN-MME

Master planning

Human Resources

• Participation of CNRS-IPNO to follow-up of components manufacture (up to ~17 man.months) in discussion

• 2 FSU (mid 2014-end 2015)• Main Workshop (and “sous-traitance”) for manufacture of tooling

(as in apt)

Summary • Cryo-module design status:

– Conceptual design: finished– Detailed design of vacuum vessel: finished, procurement

start end July– Detailed design other components: in progress, to be

finished by end 2013

• Cryo-module assembly tooling status:– Conceptual design in progress– Detailed design to be finished by end 2013

• Procurement of cryostat parts– Vacuum vessel CNRS-IPNO– Other components CERN (CMI) in 2014

• Fabrication of assembly tooling:– By CERN from CNRS-IPNO drwgs

• Assembly of cryo-module to start beginning 2015