This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871.

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Testing of Advanced RF Structures

TNA WP12 RF Test Stands

Roger Ruber (Uppsala University)

Walter Wuensch (CERN)

3rd Annual Meeting, 22 April 2020

WP12 RF Testing Facilities

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting2

The TNA within WP12 groups TWO facilities devoted to testing of superconducting RF cavities and normal conducting RF cavities.

HNOSSUppsala

University

XBOXCERN

Geneva

TASK 12.1 HNOSS

TASK 12.2 XBOX

WP12.1 UU/FREIA HNOSS Facility

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting3

The HNOSS facility at the FREIA Laboratory, Uppsala University, Sweden, is available for testing of superconducting RF cavities with integrated helium tank.

HNOSSUppsala

University

TASK 12.1 HNOSS

WP12.1 UU/FREIA HNOSS - Overview

In proposal - 4 projects with a total of 2880 access units.

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting4

Name Institutes Status Access units Users

ESS High-beta Elliptical Cavity CEA Saclay Completed.

Reported and published.

1330 18

Validation of a prototype

double spoke cavity

cryomodule

IPN Orsay Completed.

Reporting ongoing.

2048 14

RF and piezo actuators

study on spoke cavities

Lodz University

of Technology

Completed.

Reported and published.

36 8

HL-LHC crab cavity cold

testing

CERN Approved end February (480) (7)

TOTAL Achieved Today 3414 (118%) 40

WP12.1 FREIA-HNOSS-2018-01

• Validation of prototype double spoke cavity

cryomodule

• validation valve box in Dec. 2018 & Jan. 2019

• thermo-acoustic (Taconis) oscillations

→ installed RLC circuit

• cryomodule quench → rupture disk replaced

• Results

• RF conditioning → several multipacting bands

• revealed problems in RF stations and LLRF synchronization → fixed!

• stable operation at 2K

• measured accelerating gradient, heat load

→ better than target requirements

• studied Lorenz force detuning,

frequency sensitivity vs. temp., pressure

• Full Report in preparation

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting5

WP12.1 FREIA-HNOSS-2019-01

• RF and piezo actuators study on spoke cavities

• use cavities from cryomodule project HNOSS-2018-01

• Results

• measurement of piezo & cavity operational parameters,

• verified and modified specifications for spoke cavities

resonance control system

• design verification of control system and algorithms.

• main parameters of designed driver has to be modified

• triggered discussion to harmonize piezo driver

system for ESS spoke and elliptical cavities

• Report

• LLRF 2019 poster

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting6

WP12.2 CERN XBox Facility

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting7

The XBox facility at CERN, Switzerland, is available for testing ofnormal conducting RF cavities/structures at X-band frequency.

XBOXCERN

Geneva

TASK 12.2 XBOX

WP12.2 CERN XBox - Overview

In proposal - 4 projects with a total of 6000 access units.

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting8

Name Institutes Status Access units Users

Dark current and breakdown

Spectrometer

Uppsala

University

Completed.

Reported and published

1680 6

X-band pulse compression

chain

PSI and

Tsinghua

University

Underway.

First publication, PRAB.

2500 and

continues

7

X-band RF deflecting

structure testing

Lancaster

University and

SARI (Shanghai)

Preparation.

SARI structure ready for

installation, Lancaster

structure under assembly

(3000) (6)

Measurement of the

Average Power limitation for

High Gradient X-band

Accelerating Structures for

Future Light Sources

Technical

University of

Eindhoven

Approved end February (500) (5)

TOTAL Achieved Today 4180 (70%) 13

WP12.2 CERN-XBOX-2018-01

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting9

Project 2:X-band pulse compression chain

Corrector cavity chain Barrel Open Cavity Pulse Compressor

Under testing in Xbox-2, 2500 h and continuesFirst publication, PRAB.

WP12.2 CERN-XBOX-2018-01

• Validation of the high power performance

of a new pulse compressor cavity (BOC)

and correction cavity chain (CCC)

for X-band operation

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting10

klystron output

BOC output

correction cavity output

WP12.2 CERN-XBOX-2019-01

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting11

Project 3X-band RF deflecting structure testing

SARI (Shanghai) deflector cavity arrived at CERN;ready for installation

Lancaster deflector (crab) cavityunder assembly

WP12 TNA - Outlook

• A typical User Project is quite complex, often requires some form of

approval at the level of the proposing institutes, so lead times are long.

• Assuming an autumn restart, we expect that

WP12 will fulfill project and access unit requirements

by the original ARIES end date.

• If a further year is granted, Xbox projects 2, 3, and 4 will continue.

• This will increase the access units, and ease risk on delay of one of the two

structures of project 3.

WP12 Testing of Advanced RF Structures - Roger Ruber - 22-April-2020 - 3rd ARIES annual meeting12