Status of the SPL cryo-module development - Indico - Cern

Status of the SPL cryo-module development V.Parma, TE-MSC (with contributions from WG3 members)

SPL seminar, CERN 18th February 2010

Content • SPL architecture and parameters • Work organisation • Layout studies and machine sectorisation (vacuum+cryogenics) • Cryogenic scheme (for the prototype) • Supporting schemes • Next steps • Summary

Layout injector complex SPS

PS2 ISOLDE

PS

SPL

Linac4

The SPL study Goals of the study (2008-2012): • Prepare a Conceptual Design Report with costing to present to CERN’s management for approval • This is the low power SPL (LP-SPL) optimized for PS2 and LHC

10 x 6 β=0.65 cavities

High β cryomodules

5x8 β=1 cavities

High β cryomodules

13 x 8 β=1 cavities

Kinetic energy (GeV)

LP-SPL beam characteristics

Debunchers

To PS2

Medium β cryomodule

427 m 4 GeV

Ejection

186 m 1.4 GeV

110 m 0.73 GeV

TT6 to ISOLDE

From Linac4

0m 0.16 GeV

Length: ~430 m 4

Beam power at 4 GeV (MW)

0.16

Rep. period (s)

0.6

Protons/pulse (x 1014)

1.5

Average pulse current (mA)

20

Pulse duration (ms)

1.2

The SPL study (cont.d) • Study a 5 GeV and multi MW high power beam, the HP-SPL • Major interest for non-LHC physics: ISOLDEII/EURISOL/Fixed Target/Neutrino Factory

6x8 β=1 cavities

Option 1

Option 2

2.5 or 5

2.5 and 5

3 MW (2.5 GeV) or 6 MW (5 GeV)

4 MW (2.5 GeV) and 4 MW (5 GeV)

Rep. frequency (Hz)

50

50

Protons/pulse (x 1014)

1.5

2 (2.5 GeV) + 1 (5 GeV)

Av. Pulse current (mA)

20

40

Pulse duration (ms)

1.2

0.8 (2.5 GeV) + 0.4 (5 GeV)

Energy (GeV) Beam power (MW)

~500 m 5 GeV High β cryomodules

Debunchers

To PS2

High β cryomodules

Ejection

5x8 β=1 cavities

~300 m 2.5 GeV

to Eurisol

10 x 6 β=0.65 cavities

High β cryomodules

186 m 1.4 GeV Ejection

Medium β cryomodule

110 m 0.73 GeV

TT6 to ISOLDE

From Linac4

0m 0.16 GeV

12 x 8 β=1 cavities

Length: ~500 m

HP-SPL beam characteristics

Cryo--module: Goal & Motivation Cryo Goal: • Design and construct a full-scale cryo-module prototype (part of the SPL Design Study) Motivation: • Develop technologies and demonstrate construction capability on a cryo-module with 8 β=1 cavities • Learning of the critical assembly phases (e.g. clean-room) • Enable RF testing on a multi-cavity assembly in real operating conditions (horizontal cryostat) • Investigate and acquire experience on cryogenic operation issues (e.g. process control)

Working group (WG3) members System/Activity

Responsible/member

Lab

Machine architecture

F.Gerigk

CERN, BE/RF

WG3 coordination

V.Parma

CERN, TE-MSC

Cryo-module conceptual design & Integration

V.Parma, N.Bourcey, A.Vande Craen, D.Caparros, P.Coelho, Th.Renaglia

CERN, TE/MSC, EN-MME

Cryostat detailed design

P.Duthil

CNRS/IN2P3-Orsay

Cryostat assembly tooling

S.Chel

CEA-Saclay

WG 2 activity (RF cavities/He vessel/tuner, RF coupler)

W.Weingarten/S.Chel/O.Capatina/ CERN BE/RF, CEA-Saclay E.Montesinos

Vacuum systems

S.Calatroni

CERN, TE/VSC

Cryogenics

U.Wagner

CERN, TE/CRG

Survey

D.Missiaen

CERN, BE/ABP

Quad.doublet

D.Tommasini

CERN, TE/MSC

Activity of WG 3 • Regular WG meetings since May 2009 – Web page: https://twiki.cern.ch/twiki/bin/view/SPL/CryoModules

• Topics covered (or in progress): – – – – – –

Cryomodule longitudinal study SPL mechanical layouts Sectorisation issues Cryogenic cooling schemes Integration of RF Coupler Cryo-module design: supporting systems, thermal shielding,...

• Close collaboration with WG2 (cavities and ancillaries) • Relevant workshops 2009: – Workshop on Mechanical issues of SPL cavities/cryomodules: http://indico.cern.ch/conferenceDisplay.py?confId=68968 – Workshop on Cryogenic and vacuum sectorisation of the SPL: http://indico.cern.ch/conferenceDisplay.py?confId=68499

• Coming up soon (16-17 March): Review of the RF Couplers

Planned supplies for prototype cryocryo-module Institute

Responsible person

Description of contribution

CEA – Saclay (F)

S. Chel

1. Design & construction of 2 β=1 cavities (EuCARD task 10.2.2) 2. Design & construction of 2 helium vessels for β=1 cavities (French in-kind contribution) 3. Design & construction of cryostat assembly tools (French inkind contribution) 4. Supply of 8 tuners (French in-kind contribution)

CNRS - IPN – Orsay (F)

P. Duthil

1. Design and construction of prototype cryomodule cryostat (French in-kind contribution)

Stony Brook/BNL/AES team

I.Ben-zvi

(Under DOE grant) 1. Designing, building and testing of 1 β=1 SPL cavity.

CERN

O.Capatina

1. 8 β=1 cavities 2. 7 He tanks in titanium 3. 1 He tank in st.steel

CERN

E.Montesinos

1. 10 RF couplers (testing in CEA, French in-kind contribution)

Cryo-module Cryolongitudinal integration study (β (β=1) =1)

+

Longitudinal mechanical layouts «Continuous» vs. «fully segmented» cryostat SPL layouts Continuous cryostat "Compact" version (gain on interconnections):

è 5 Gev version (HP): SPL length = 485 m (550 m max available space)

"Warm quadrupole" version (with separate cryoline):

è 5 Gev version (HP): SPL length = 535 m

(550 m max available space)

CRYOGENICS AND VACUUM SECTORISATION Outcome of workshop on cryogenic and vacuum sectorisations of the SPL (November 9-10, 2009)

Possible cryogenic feeding: “continuous” cryostat Cryo-plant

Isolde extraction

CIB

Cryogenic Interconnect Box Cryo Unit Cryogenic bridge

Eurisol extraction

“continuous” cryostat • • • •

“Long” and “continuous” string of cavities in common cryostat Cold beam tube “straight” cryogenic lines in main cryostat common insulation vacuum (between vacuum barriers, if any present)

String of cryo-modules between TSM Technical Service Module (TSM) Cold-Warm Transition (CWT) Insulation vacuum barrier Warm beam vacuum gate valve

Possible cryogenic feeding: Cryogenic Distribution Line Cryo-plant

Isolde extraction

CIB

Cryogenic Interconnect Box Cryo-module Units Cryogenic Distribution Line

Eurisol extraction

“segmented” cryostat • • • •

Cryostat is “segmented”: strings of (or single) cryo-modules, 2 CWT each Warm beam zones Cryogenic Distributio Line (CDL) needed Individual insulation vacuum on every string of cryo-module (Vacuum Barriers, w.r.t. CDL) Cryogenic Distribution Line (CDL) String of (or single) cryo-modules Technical Service Module (TSM) Cold-Warm Transition (CWT) Insulation vacuum barrier Warm beam vacuum gate valve

Main issues •

Machine availability: –

•

“work-horse” in the injection chain

Reliability of built-in components and operational risks – Typical faults expected on: cavities, couplers, tuners... – Operation with degraded performance (cavities, optics, leaks...)

•

Maintainability: – Warm-up/cool-down . Time and reliability. Need for partial or complete warm-up of strings to replace built-in components or even one cryo-module – Accessability of components for regular maintenance or repair

•

Design complexity of compared solutions

•

Operational complexity (e.g.cryogenics with 1.7% slope)

•

Installation and commissioning

•

Safety. Coping with incidents (MCI): Loss of beam and/or insulation vacuum (helium and air leaks):

•

Cost differences between options

VACUUM

SPL Sectorisation Variants

Continuous

Segmented Option A

Segmented Option B

Vacuum sectorisation

22

09/11/09

Summary: comparison of vacuum aspects Drawbacks

Advantages

Drawbacks

-Compact long.layout -fewer components -Reduced vac systems (integrated He lines)

- Long beam vacuum sectors , cold sector valves don’t exist! - Some sensitive equipment needs vacuum compatibility and validation

-Modular design - Easier access, repairs, upgrades - Modules are complete & tested before installation

-More vacuum components (eg CWT) -More vacuum instrumentation

-Insulation vacuum systems are exposed to tunnel environment - Beam/cavity vacuum more exposed?

-Minimize tunnel work/problems modules are complete and tested before installation - Staged acceptance tests - Decoupling of problems

- Equipment will see more thermal cycles –> create leaks?

- Reduced search/repair zones - Reduced coactivity - Local warm-up and opening of vacuum system – cost & downtime

- Difficult access at CWT – not std interconnect design

- Cavities re-commissioning after venting -RF processing with helium required for field above < 6 MV/m - Movable blocks or valves to absorb field emission electrons?

-Pre-commissioning before installation - Staged tests – smoothing of resources, - Earlier identification of problems - Decoupling of problems - Re-commissioning of ‘weak’ module possible

- More volumes to commission

MCI would affect more equipment

- Limit MCI affected zone by interlocked beam vacuum valves - Limit zone of degraded ins vacuum (helium leak) - Easier diagnosis of problems

- More equipment (fixed pumping systems & valves) - More interlocks - More risk of equipment failure - More maintenance

Repair

- Less tasks for systematic repairs on modules – venting, re-pumping..

Commisioning Operation

Segmented with CDL

Advantages

Installation

Design

“continuous” cryostat

Simpler controls Redundancy in fixed pumping systems

CRYOGENICS

Cryogenics • Cavities cooled with helium II at ~ 2.0 K (3.1 kPa), similar to XFEL – Cavities inside saturated bath (slightly sub-cooled due to hydrostatic head) – Profit from low Δp and good p-stability

Vapor flow large JT Vapour Liquid

Beam tube

Gas return tube Two phase tube

support

2.2 K forward 2 K return

5 K forward

80 K return

40 K forward 300 mm

8 K return 2 K 2-phase

cool down/ warmup

Effect of slope cavity coupler

XFEL

Module Schemes Scheme no 3: “ILC-like”

1.7 %

Diameter “x” [mm]

SPL Workshop NOv. 2009

26

LP SPL

HP SPL

40

80

6/11/2009

Module Schemes Scheme no 7 : “ILC like SPL version “A” with separate cryogenic line equipped for independent cool-down, warm-up and purge”

1.7 %

SPL Workshop NOv. 2009

27

6/11/2009

Separate cryogenic line Advantages / Disadvantages

• Advantages • Less complexity for the main cryostat • Potential to completely isolate “faulty” modules

• Disadvantages • Requires more tunnel space • Higher static heat load

• Cost aspect • Not easy to identify separate line most probably more expensive • More complex cryostat and installation vs. cryostat plus line, two installations and more tunnel space SPL Workshop NOv. 2009

28

6/11/2009

modified cryogenic scheme (proposal)

Warm valves Warm recovery line

Cryogenic issues (ongoing) • High dynamic heat load: ~200 W/cryo-module (~25 W/m)! – Thermal break-down to be checked (q