1 Requirements Conformance for SRF cryomodules 15-16 October 2014 Lund P. Bosland (on behalf of the CEA/Irfu and CNRS/IPNO teams) ESS elliptical cryomodules.

1Requirements Conformance for SRF cryomodules 15-16 October 2014

Lund

P. Bosland(on behalf of the CEA/Irfu and CNRS/IPNO teams)

ESS elliptical cryomodulesTwo families of elliptical cavities:

Medium beta: b=0,67High beta: b=0,86(geometrical beta values)Same cryostat for both types of cavities


Lund

Cryomodule sub-system

Segmented LINAC:

Independent cryogenic cooling and control

Warm-up of a individual cryostat is possible

Individually removable cryostats for repair is

possible

Focusing elements at warm temperature


Lund

IPN ORSAY: cryostat design and fabrication

Vacuum vessel Space frame – cavity supports Thermal screen Superinsulation Internal cryogenic pipes Instrumentation

CEA SACLAY: “cavity package”, the cryomodule assembly and RF power tests

Cavities + helium tank Power coupler design, manufacturing,

RF tests Piezo tuner Magnetic shield Tooling: field flatness, cavity preparation, cryomodule

assembling, … Cryomodule assembly Tests stand for cryogenic and RF power tests Tests of the ECCTD cryomodule

Two prototype cryomodules

M-ECCTD with medium beta cavities - 2012 – 2016

FR-SW agreement

Collaboration IPNO and IRFU

H-ECCTD with high beta cavities - 2014 – 2017

French In-kind contribution

The IRFU - IPNO collaboration


Lund

Cryomodule Design

• total length: 6.6 m• Beam height: 1.5 m

Similar to CEBAF/SNS cryomodule with 4 cavities per cryomodule

Common design for medium (6 cells) and high beta (5 cells) cavity

cryomodules

Accelerating gradient:for b=0.67 (Medium Beta): Eacc=16.7 MV/m Qo> 5E9 at 2 Kfor b=0.86 (High Beta): Eacc=19.9 MV/m Qo> 5E9 at 2 K

Maximum operating helium pressure: 1.431 bar


Lund

57,5 mm

Medium / High beta cavity

High beta (0,86): - 5 cells- Length

1316,91mm

Medium beta (0,67): - 6 cells- Length

1259,40mm

Medium High

Geometrical beta 0.67 0.86

Frequency (MHz) 704.42

Operating temperature (K)

2

Maximum surface field in operation (MV/m)

44 44

Nominal Accelerating gradient (MV/m)

16.7 19.9

Nominal Accelerating Voltage (MV)

14,3 18,2

Q0 at nominal gradient > 5e9

Cavity dynamic heat load (W)

4,9 6,5

Qext 7.5 105 7.6 105Medium High

Iris diameter (mm) 94 120Cell to cell coupling k (%) 1.22 1.8

p and 5p/6 (or 4p/5) mode separation (MHz) 0.54 1.2

Epk/Eacc 2.36 2.2Bpk/Eacc (mT/(MV/m)) 4.79 4.3Maximum. r/Q (W) 394 477Optimum b 0.705 0.92G (W) 196.63 241

No HOM couplersHOM frequencies must be carefully

controlled

Tank (Ti) Magnetic shielding Cold tuning

system


Lund

Fundamental power coupler

Coupler conditioning set-up

Pmax = 1.2 MW peak at 4 % duty cycle → critical component

RF ceramic window Inner conductor

• Conical tip for stronger coupling• Water cooling

Outer conductor• Cooled with Liquid He in the vac. Vessel

Coax to rectangular RF transition (Door Knob)• HV bias with RF trap

CM integration• Large diameter flange with below on vacuum vessel• Diagnostic ports distribution


Lund

Rods (TA6V, Diam. 6mm)

Magnetic shield

Half rings linked to the tank (under the magnetic shield)

Supports of the different cold components

• Cross rods fixed on 2 titanium

half rings fastened to the helium

tank on one side and on the

spaceframe on the other side

• 3000N pre-stress applied on the

rods, maximum force 8500N per

rod after cooling down

• Special boxes allowing the axial moving and

the thermalization of the thermal shield

Thermal shield

Supporting rods• 2 wheels fixed to the spaceframe at each extremity

• Guiding ensured by two rails welded to the vacuum vessel

3 jacks at 120° supporting the spaceframe after insertion

Rod

Pre-stress nut

Blocking nut


Lund

Inter-cavities bellows

HIGH BETANumber of corrugations: 6Overall length 183mm (at rest)Axial stiffness for 6 corrugations 35N/mmRadial stroke for 6 corrugations +/-0.48mmRadial stiffness for 6 corrugations 7417N/mm

MEDIUM BETANumber of corrugations: 10Overall length 240,5mmAxial stiffness for 10 corrugations 21N/mmRadial stroke for 10 corrugations +/-0.80mmRadial stiffness for 10 corrugations 4450N/mm

Cold to warm transition

Mechanical cavity misalignment on the cavity stringsLongitudinal shrinkage of the cavitiesThermal isolation at the two extremities of the cryomodule

Distribution of the RF HOM modes


Lund

Depl. Total(mm)

Depl. Struct.(mm)

Depl. Blocs(mm)

Contrainte max (Mpa)

1,321,24

(Z: -1,21 à +0,50)

0,12 à 1,08(Z: -0,89 à

+0,18)30

Spaceframe

Forces on Rods: 3000 to 9000N

Mass spaceframe: 400 - 430 KgTotal mass of cavities + thermal shielding: 1200Kg

Blocking by 3 jacks on two levels

Tuning (3 positions)

Spaceframe:• Aluminium alloy• Lower part can be

disassembled to insert the couplers


Lund

Access traps

blocking of the cavities and

spaceframe during transport

Access in the tunnel Maintenance of cold tuning

system (change motor and piezo)


Lund

Reflector brackets(coupler flange)

Reflector brackets(cavity flange)

Alignment made by laser tracker

Alignment of the cryomodule in the tunnel (source ESS)

1,5" Corner cube reflector

Additional fiducials will be set up inside the ECCTD cryomodule to check the alignment after cooling down.

Alignement of the cavities

Reflector brackets(vessel alignment)

Alignment of the cavity string within 1,5 mm of the beam axis

1 2

3 4

Beam axis reported to reflector bracket on beam flanges

Vessel alignment with respect to cavity string


Lund

Medium beta High beta 50K 2-5K 50K 2-5K Stat. Dyn. Stat. Dyn. Stat. Dyn. Stat. Dyn. Cavity string Beam losses (0.5W/m) 3.25 3.25 RF losses 20 24.4 Radiations (14m2) 0.7 0.7 Cold to warm transition (x2) 3 2 3 2 Supporting system 6 0.25 6 0.25 Helium piping Supporting system 0.2 0.4 0.2 0.4 Bursting disks (x2) 3 0.15 3 0.15 Helium valves (x2) 1 0.2 1 0.2 Safety relief valves (x2) 0.03 0.03 0.03 0.03 Thermal shield radiations (21m2) 31.5 31.5 Couplers (x4) Sleeve cooling (4*23 mg SHe at 5K) 4 (4) 4 (4) Radiation from antenna to cavity 2.8 2.8 Instrumentation, heaters and actuators 1.5 2.7 1.5 2.7 TOTAL Static load 46.23 13.23 46.23 13.23 TOTAL Dynamic load 23.25 27.65

TOTAL 46.5 37 46.5 41

Heat loadsValues in Watts


Lund

Helium cooling PID

• Special boxes allowing the axial moving and the thermalization of the thermal

shield


Lund

Compliance with the PED97/23/EC

Vessels Pipes

PS<0,5bar:The equipment is not on the scope of the 97/23/CE directive

Article 3.3The equipment must be designed and manufactured according to workmanlike way

Category IThe manufacturing must be more documented, especially with internal production control

Objective: stay within « Article 3.3 » area

50 L

Elliptical cavity1 bar

Relative pressure


Lund

SAFETY DEVICES

European rules compliance Article 3.3

ESS Helium factory, circuits and operating modes

Helium Pressure relief devices

Working pressure = nominal pressureWP

PSET Set PressurePS

Maximum allowable overpressure PS + 10%

BURSTING DISK

SAFETY DEVICES

PSET

POPENING = + 5 % PSET

(overpressure when opening)PMAX APERTURE = + 10 % POPENING

PCLOSING = - 5 % PSET

PMIN CLOSING = - 10 % PCLOSING

(hysteresis before closing)

PSET + 10%

PSET – 10%

RELIEF VALVE

Bursting area

Opening area

WP upper limit

Max. allowable press.

Safety margin

Safety margin

1,9 bar

1,431 bar(1,3 +10%)

1,729 bar

1,301 bar

MAWP 1,58bar

1,670 bar

1,496 bar

1,891 bar

59mbar

65mbar

1,81 bar

Bursting disks+/- 10%

2,09 bar

Cavity pressure test1,43 PS 2,72 bar

1,609 bar

1,551 bar

Absolute pressure


Lund

Helium low pressure circuit

2 bursting disk at each tip+ upstream safety relief valve (with he guard)

36°

Heat exchanger

The circuit is designed to reduce as low as possible the overpressure in case of beam vacuum failure by using a continuous DN100 diameter for the diphasic pipe, large curvatures and 2 DN100 bursting disks at each extremity.

A 36° angle is set up for the tank nozzle in order to allow the insertion of the cavity string and the cooling circuit inside the spaceframe

To valve box

Worst scenario: beam vacuum failure 38KW/m2 heat load on the cavity wall Accidental overpressure: 230mbar after rupture of the disks


Lund

Status of the M-ECCTD

Cavities: Design finished Medium beta: fabrication started (KO meeting 03/09/2014)

Couplers: RF window and antenna ordered Call for tender for outer conductor (double wall) and door-knob to

be launched in the following weeks Tuners, magnetic shielding:

Design 95% finalized Fabrication to be launched

Spaceframe, vacuum vessel: Design finalized. Preparation of the procurement procedures in

progress(goal: launch the procurement before the end of January 2015)

Test stand: modification of the cryogenic line and HV modulator in progress

Clean room assembly toolings: studies started - still in progress


Lund

18

2 prototype high beta cavities haut béta have been tested: The 2 cavités ZANON et RI are within the ESS specifications.

19ESS cryomodules Workshop 15-16 October 2014 Lund

Cryomodule assembly


Lund

M-ECCTDTwo objectives:

1. To qualify the technology

2. To prepare the assembly procedures, the tools and the documentation for the serial elliptical cavity cryomodules

Assembly procedure

Integration tools

Documentation

Others

Items manufacturing

ECCTDintegration

Assembly procedure

Integration tools

Documentation

Others

Rea

dy f

or t

he s

eria

l cry

omod

ules

Preliminary Version Final Version


Lund

Study of the assembling sequence and needs of toolings

Pre-study of the toolings: compatible with both types of cavities medium and high beta

Assembling in clean room Assembling outside clean room

Student: Amaury Martin09/2013 – 01/2014

Analyse of the assembling sequence


Lund

Coupler / cavity assembly

State of the art: interface coupler / cavity parallel to the laminar air flow

Horizontal coupler

Rotation needed after assembly to get to the final vertical position of the coupler in the cryomodule

Complex tooling First rough analysis of the air flow around the

flange: the air flow may be pertubated because of the reinforcement sheets of the helium tank

Air speed Whirlwind

Cou

ple

r vert

ical

Cou

ple

r h

ori

zon

tal

Choice: vertical assembly

Tooling compatible for both types types of cavities

Adjustment of the coupler position relative to the cavity flange


Lund

Frame and supports for the assembly in clean room


Lund

Cavity string assembly in clean room

Design still in progress

Beam axis height: 1150 mm from the clean room ground

Individual position adjustment system of each cavity and bellow

Supports of the cold to warm transition bellows to be designed


Lund

Assembly outside clean room

Thermal screen installed but not shown

•Wheels on the spaceframe

•Guiding rail on the vacuum

tank


Lund

Conclusion .

The implementation of the assembling process at Saclay will be based on the

SPIRAL2 and XFEL experience

Courtesy of Spiral 2 CEA team

Courtesy of Catherine MADEC - XFEL


Lund

# CODE ACTIVITY DESCRIPTION Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

16 11.5.1 MEDIUM BETA STRUCTURES

17 M-ECCTD Prototyping (WP3,5,7,8) M-ECCTD qualified (2016.09.30)

18 Niobium: procurement and fabrication

19 Cavities : procurement and fabrication

20 Couplers : procurement and fabrication

21 Tuners : procurement and fabrication

22 Cryostat components : procurement and fabrication

23 Cryomodule assembly: procurement and fabrication

24 Klystron/modulator: procurement, fabrication and FAT

25 Klystron/modulator: SAT + control/system s i te preleminary tests Klystron/modulator available (2017.03.31)

26 Cavi ty tests in vertical cryostats

27 Couplers RF process ing

28 Cryomodules assembly

29 Cryomodules power qual ifi cation test (three fi rst)

30 Transport First protons on target

31 11.5.2 HIGH BETA STRUCTURES

32 Prototyping (WP3,5,7,8) H-ECCTD qualified (2017.11.14)

33 Niobium: procurement and fabrication

34 Cavities : procurement and fabrication

35 Couplers : procurement and fabrication

36 Tuners : procurement and fabrication

37 Cryostat components : procurement and fabrication

38 Cavi ty tests in vertical cryostats

39 Couplers RF process ing

40 Cryomodules assembly

41 Cryomodules power qual ifi cation test (three fi rst)

42 Transport

2019 2020 2021 20222013 2014 2015 2016 2017 2018


Lund

Thank you for your attention

1 Requirements Conformance for SRF cryomodules 15-16 October 2014 Lund P. Bosland (on behalf of the CEA/Irfu and CNRS/IPNO teams) ESS elliptical cryomodules.

Documents