Medium Beta Cavities

Paolo Michelato, Paolo Pierini, and Carlo PaganiINFN Milano - LASA

INFN IN-kind contribution proposal• Medium beta and high beta cavities prototyping

– Procurement contract NOT included in the proposal.• Medium beta series cavities

– Niobium procurement for the fabrication of 36 medium beta cavities.– Cavity fabrication of 36 (*) medium beta cavities in the industry,

including treatments, tuning, Helium tank integration, etc, accomplishing the ESS requirements in terms of performances, functional interfaces.

– Certification activities, documentation, ancillaries (flanges, vacuum valves, antennas, frames, etc.)

– Cold test in a qualified infrastructure.– Transportation in special boxes and delivery at the cryomodule

assembling facility.– Man power for the above activities.(*) INFN Design, plug compatible with CEA boundary condition

INFN - LASA strategy for prototypes• Built prototypes of both medium and high beta cavities.

– INFN design, using LG Nb, plug compatible with ESS cryomodule.• Design process in progress.

– Optimization to include LG option.• LG Nb ingots procurement started.

– Slicing process ordered.• Full treatment (BCP, HPR, clean room) done in industry. • Final handling and test will be done at LASA in the qualified

infrastructure.

INFN proposal time plan (Feb 2015)

CEA revised scheduling proposed

INFN – LASA experience on SC cavities

• SNS cavities• TRASCO cavities• PDS-XADS cavities• EUROTRANS/MAX Elliptical test cryomodule• TTF/Tesla & FLASH cavities and modules• European XFEL series production of 1.3 GHz cavities• European XFEL 3.9 GHz system

PDS-XADS_WP3 1st MeetingNice, December 10-11, 2001Carlo Pagani 7

g = 0.61 Cavity for SNS – 4 dies

Ep/Eacc 2.72 (2.63 inner cell)Bp/Eacc [mT/(MV/m)] 5.73 (5.44 inner cell)R/Q [] 279G [] 214k [%] 1.53QBCS @ 2 K [109] 27.8Frequency [MHz] 805.00Field Flatness [%] 2

KL70 = -2.9 [Hz/(MV/m)2] KL80 = -3.4 [Hz/(MV/m)2]

Nb thickness = 3.8 mm

Effective that matches the TTF curve = 0.630

Geometrical ParametersInner cell End Cell Left End Group (coupler)

Left RightL [mm] 56.8 56.8 56.8Riris [mm] 43.0 43.0 43.0 65.0D [mm] 163.76 163.76 166.98d [mm] 11.0 11.0 11.0 10.0r 1.7 1.5 1.7 1.5R 1.0 1.0 1.0 [deg] 7.0 8.36 7.0 10.0

g = 0.81 Cavity for SNS – 4 dies

Ep/Eacc 2.19 (2.14 inner cell)Bp/Eacc [mT/(MV/m)] 4.79 (4.58 inner cell)R/Q [] 485G [] 233k [%] 1.52QBCS @ 2 K [109] 36.2Frequency [MHz] 805.00Field Flatness [%] 1.1

KL70 = -0.7 [Hz/(MV/m)2] KL80 = -0.8 [Hz/(MV/m)2]

Nb thickness = 3.8 mm

Effective that matches the TTF curve = 0.830

Geometrical ParametersInner cell End Cell Left End Group (coupler)

Left RightL [mm] 75.5 75.5 75.5Riris [mm] 48.8 48.8 48.8 70.0D [mm] 164.15 164.15 166.11d [mm] 15.0 13.0 15.0 13.0r 1.8 1.6 1.8 1.6R 1.0 1.0 1.0 [deg] 7.0 10.072 7.0 10.0

6 cells =0.61 cavity 6SNS61-1Q0 vs. Eacc

1.00E+09

1.00E+10

1.00E+11

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0

Eacc [MV/m]

Q0

T=1.94K T=1.96K T=1.96K - 20' RF processing

Test #3

6 cells =0.81 cavity 6SNS81-1 stiffening ring at 80mmQ0 vs. Eacc

1.00E+09

1.00E+10

1.00E+11

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Eacc [MV/m]

Q0

T=1.94K T=2K T=1.96K T=2.09K

Test #1

After 20' He processing

Design goal

Experimental Results1st Prototypes

INFN Cavity Design TJNAF FabricationBased on INFN Design & TTF Technology

G. Ciovati, former student of mine, working at TJNAF on SNS cavities

MoU between INFN and TJNAF “for thr Development of low

Superconducting Cavities for Proton Accelerators”

From TTF Experience, INFN Contribution to SNS

8

XFEL 1.3 GHz SC Cavities:Overview

Two Companies committed for the 400 + 400 1.3GHz cavities production: E. Zanon (EZ) and Research Instruments (RI). Up to now 630 cavities have been produced.Main steps at the Companies:

Mechanical fabrication & RF measurements and TuningSurface treatments (BCP/EP, HPR, thermal treatments, etc.)He-tank integrationShipment to DESY for cold RF test (cavity equipped with all ancillaries)

Cavities integrated in the He-Tanks and ready to be cold RF tested at DESY (foreseen production rate: 3.5-4 cav/week):INFN-DESY supervise the full cavities production:

Technology transfer to industry Infrastructures ramp-up and qualification (clean room, UP water,

EP/BCP systems, HPR, thermal treatments, vacuum, etc.)Quality control of the on-going production

9

XFEL 3.9 GHz third Harmonic SC Cavities:Vertical RF Test Results

INFN has the full responsibility (design and production) of the 3.9 GHz Cryomodule (8 cav + 2 spares)

10 cavities produced, with all accessories: He-tank, Blade Tuner, magnetic shield.

Cryomodule already at DESY

All cavities successfully tested at LASA above specs.

Module in tunnel Summer 2015

T = 2 K

Cav 3HZ010Horizontal Test

1st Test!

10

XFEL 3.9 GHz third Harmonic SC Cavities

Preparation for vertical test

3HZ010: successful horizontal test at DESY Eacc: up to 23.8 MV/m at 1st test

Stable operation for > 48 h at >20 MV/m with nominal EXFEL beam parameters

27/03/2015

INFN Plug-compatible designjust started but well in progress - 1

INFN Plug-compatible designjust started but well in progress - 2

Inner cell parameters

INFN Plug-compatible design3D model for ANSYS HFSS