12.4: srf hom diagnostics: experimental results and future plans

12.4: SRF HOM Diagnostics:Experimental Results and Future Plans

Nicoleta Baboi*, Liangliang Shi*# *DESY; #UMAN

for the HOM-team

EuCARD2 WP12 Meeting16 April 2014, Saclay

Task 12.4: SRF HOM Beam Diagnostics: Experimental Results, Baboi | EuCARD-2 WP12 Meeting, CEA Saclay | 16 April 2014 |

>HOM-based beam diagnostics for the European XFEL (E-XFEL)

Beam phase (wrt RF) and position In 3.9 GHz and 1.3 GHz cavities

Strong interconnection to the FLASH linac

> Benefits Reduction in emittance dilution from transverse wakefields by

centering beam in accelerating cavities Direct, on-line measurement of beam phase wrt RF phase Additional beam position monitoring

Aim


> Introduction Principle The European XFEL and FLASH Overview of HOM-based diagnostics

>HOM-based beam position monitoring for 1.3GHz cavities for 3.9GHz cavities

>HOM-based beam phase monitoring for 1.3GHz cavities [for 3.9GHz cavities]

> Partial summary

> Stability study → Liangliang Shi

Contents


Phase difference

Principle

> Filter higher dipole mode for beam position

> Filter higher monopole mode for beam phase

×

Beam offset [mm]


The European XFEL

accelerating structures

experimental hall

http://www.xfel.eu/

undulators


FLASH


Accelerating Cavities for the E-XFEL and FLASH

The 1st dipole band

HOMBPM

The 1st dipole bandThe 2nd

dipole band

Coupled cavities


FLASH E-XFEL

1.3 GHz Cavities

- Proof-Of-Principle made (SLAC/CEA/DESY)

- Tests for E-XFEL to be made in FLASH

- Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)

- To be tested in FLASH

- EuCARD2: experimental studies

3.9 GHz Cavities

- So far no isolated monopole mode identified, which could be used for phase monitoring

- Theoretical (and experimental) studies (lower priority in EuCARD2)

- Same as for FLASH

Status and Plans for HOM-based Beam Position Monitoring (HOM-BPM)

FLASH E-XFEL

1.3 GHz Cavities

- Electronics installed in 40 cavities (SLAC/CEA/DESY)

- Raw signals used for beam centering- EuCARD2: Unstable calibration

- started stability studies (L. Shi’s talk)

- Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)

- Next to be tested with beam

3.9 GHz Cavities

- Theoretical and experimental studies (EuCARD + FNAL)

- Defined specs for HOM-BPM electronics (also for E-XFEL)

- Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL

- EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)

- To add to stability study for 1.3

- Electronics under design, based on same frequency ranges as for FLASH (DESY)

- But much more challenging:8 coupled cavities cf. 44.5 cf 1 MHz bunch frequencyDifferent orientation of cavities

- EuCARD2: Need significant theoretical and experimental studies (next talks)


Status and Plans for HOM-based Beam Phase Monitoring

FLASH E-XFEL

1.3 GHz Cavities



(phase or even frequency drifts?)- started stability studies (L. Shi)


3.9 GHz Cavities









FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH


FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH

Status and Plans for HOM-BPM / 1.3 GHz cavities / FLASH

FLASH E-XFEL

1.3 GHz Cavities

- Electronics installed in 40 cavities (SLAC/CEA/DESY; 2006)





3.9 GHz Cavities









Past experience / Achieved past year / Under work / EuCARD-2 challenges


FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH

Status and Plans for HOM-BPM / 1.3 GHz cavities / E-XFEL

FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities











ADC

CLK

1.3 GHz

1.7 GHz

2.4 GHz

A

A

A

Data To FPGA

Input signal

> Single channel: Direct sampling of all three frequencies without any downconversion mTCA standard

HOM-BPM / 1.3 GHz cavities / E-XFEL:Electronics Designed and Tested in Lab

RTM side AMC side

Samer Bou-Habib, WUT, DESY


RF1....RF8

REF (RF-backplane)

REF FP

6

8

CLK

+DistributionCLK out

> System architecture 8 channels

HOM-BPM / 1.3 GHz cavities / E-XFEL:Electronics Designed and Tested in Lab (2)

RTM side AMC side

DRTM-HOM DAMC-DS800



> Filter test board two filters, one on each side each for 3 frequencies (1.3/1.7/2.4)

> Example measurement Attenuation settings: -8dB @1.3 GHz,

-16db @ 1.7 GHz, -24dB @dB The filter should be tuned and then

implemented in an 8 channel RTM

HOM-BPM / 1.3 GHz cavities / E-XFEL:Electronics Designed and Tested in Lab (3)

RF1....RF8

REF (RF-backplane)

REF FP

6

8

CLK

+DistributionCLK out

DR

TM

-H

OM


FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH

Status and Plans for HOM-BPM / 3.9 GHz cavities / FLASH

FLASH E-XFEL

1.3 GHz Cavities



- started stability studies (L. Shi)



3.9 GHz Cavities





- Will add to stability study for 1.3






HOM-BPM / 3.9 GHz cavities / FLASH:Electronics from FNAL Installed

BandpassFilter

~5.43 GHz or 9.06 GHz100 MHz BW

Mixer

uTCA DigitizerSIS8300

(108MS/sec)

LO

30 MHz IF

Nathan Eddy, FNAL


HOM-BPM / 3.9 GHz cavities / FLASH: 5GHz Downconverter and PLL Boards

Nathan Eddy, FNAL


HOM-BPM / 3.9 GHz cavities / FLASH:First Beam signals on scope

> 5 GHz (C1H2) > 9 GHz (C1H1)

Signals from 9 bunches


HOM-BPM / 3.9 GHz cavities / FLASH:Raw ADC Signals in DOOCS

Each plot: signal from one HOM coupler

Signals from 2 bunches


FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH

Status and Plans for HOM-BPM / 3.9 GHz cavities / E-XFEL

FLASH E-XFEL

1.3 GHz Cavities



- started stability studies (L. Shi)



3.9 GHz Cavities











HOM-BPM / 3.9 GHz cavities / E-XFEL:Design of 5 GHz Down-converter ready

BandpassFilter


Mixer


(108MS/sec)

LO30 MHz IF

Thomas Wamsat, DESY


HOM-BPM / 3.9 GHz cavities / E-XFEL:Design of 5 GHz PLL ready

>Design of 9 GHz DCW and PLL under work

Thomas Wamsat, DESY


FLASH E-XFEL

1.3 GHz Cavities





3.9 GHz Cavities









FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH

Status and Plans for HOM-PhMon / 1.3 GHz cavities



ADC

CLK

1.3 GHz

1.7 GHz

2.4 GHz

A

A

A

Data To FPGA

Input signal

> Same as electronics as presented for HOM-BPM / 1.3GHz

HOM-PhMon / 1.3 GHz cavities / E-XFEL:Electronics Designed and Tested in Lab

RTM side AMC side



FLASH E-XFEL

1.3 GHz Cavities





3.9 GHz Cavities









FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities


- Theoretical (and experimental) studies (low priority in EuCARD2)

- Same as for FLASH

Status and Plans for HOM-based Beam Phase Monitoring



>Report on the design of electronics for XFEL-HOM diagnostics (M18)

Good progress: 1.3GHz cavities

design readytests to be made with beam

3.9GHz cavitiesDesign for 5GHz channels ready1st boards should be ready in May and then tested in labDesign of 9GHz channels will follow

1st Deliverable Approaching


>HOM-based BPMs for 1.3GHz cavities:

prev. experience with electronics at FLASHDesign of electronics for the XFEL finished -> 1st milestoneNext: Tests with beam

for 3.9GHz cavitiesFNAL electronics installed at FLASHE-XFEL electronics: design in advanced stage -> 1st milestoneNext: Tests in lab and with beam

>HOM-based phase monitoring for 1.3GHz cavities

Design of electronics for the XFEL finished -> 1st milestoneNext: Tests with beam

Not for 3.9GHz cavities

> Part 2: Stability study → Liangliang Shi

Summary of Part 1


Part 2: Liangliang Shi

FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities



- Same as for FLASH

FLASH E-XFEL

1.3 GHz Cavities






3.9 GHz Cavities





- Will add to stability study for 1.3






Thank you!


Reserve Slides:


Subtask 10.5.1 Two Choices for HOMBPM Electronics

Localized modes9060 MHz

“Common position” of power minimum

Integrated

powerRMS Error at Module Center

Coupled modes5437 MHz

Pei Zhang


> Based on EuCARD work, specs defined for HOMBPM electronics for FLASH

The European XFELMore research necessary, since there will be 8 cavities in 3.9 GHz

module (EuCARD2, incl. 1.3 GHz cavities)

Specs for Final Electronics for FLASH defined

Brian Fellenz, Nathan Eddy, Fermilab

BandpassFilter


Mixer


(108MS/sec)

LO

30 MHz IF

Position type Resolution # of channels

Local position in the cavity ~ 50-100 μm 6 HOM couplers

Global position over the module ~ 20-30 μm 2 HOM couplers


Challenges

Pei Zhang Page 33HOMSC12, Cockcroft Institute, Jun 26th, 2012

Dipole beam-pipe modes

Fundamental band

The 1st and 2nd dipole band The 5th dipole band

Large R/Q’sModes

propagate


Electronics for 3.9GHz/FLASH from FNAL: Design

CA

N B

US

CO

NT

RO

LLE

RB

OA

RD

CAN I/O

5 G

Hz

PLL

9 G

Hz

PLL

BP

F

BP

F

BP

F

BP

F

BP

F

BP

F

BP

F

9GHz DOWNCONVERTERS [30 MHz OUT]

5 GHz DOWNCONVERTERS [30MHz OUT]

5 GHz & 9GHz DOWNCONVERTERS [30 MHz OUT]

81MHzINPUTS

BP

F

BP

F

BP

F

9 G

Hz

DC

5 G

Hz

DC

5 G

Hz

DC

5 G

Hz

DC

9 G

Hz

DC

9 G

Hz

DC

9 G

Hz

DC

9 G

Hz

DC

9 G

Hz

DC

9 G

Hz

DC

4-WAYSPLITTER

8-W

AY

S

PLI

TT

ER

9GHz DOWNCONVERTERS

IN 1IN 2IN 3IN 4IN 5IN 6IN IN IN IN

5 GHz & 9GHz DOWNCONVERTERSFOR PHASE MEASUREMENTS

5 GHz DOWNCONVERTERS

P. S.+15V

P. S.+7V

9GHz 5GHzLO MON. OUT


5GHz Downconverter Board from FNAL

ATTEN 5-Bits

0-31 dB

30MHz BPFBW: 15MHz

40MHz LPF-20 dB

36 dB GAIN

+7V

IF Mon.

Output30 MHz14 dB

RFMonitor

-20 dB

-10 dB

RF DET.

19 dB

18 dB 18 dB

18 dB

LOMonitor

Output30 MHz

LOINPUT

LO MON

I MON

RFINPUT

-2 dB

GAIN CTRL


9GHz Downconverter Board from FNAL

ATTEN 5-Bits

0-31 dB

30MHz BPFBW: 15MHz 40MHz LPF

-6 dB

36 dB GAIN

+7V

IF Mon.

Output30 MHz19 dB 19 dB

RFMonitor

-20 dB

-10 dB

RF DET.

19 dB

18 dB 18 dB

18 dB

LOMonitor

Output30 MHz

LOINPUT

LO MONI MON

RFINPUT


5GHz PLL Board from FNAL

REF

81MHz BPFBW: 7MHz

LOOP FILTER

3 dB

+7V

5 GHzOUTPUT+8 dBm

15 dB2-WAYSPLITTER

Output81.25 MHz

SC

KS

DI

SE

NR

ST

BS

DO

CP

RF

HMC702LP6CE PLL

HMC430LP4 VCO

+15V

16dB

TEST CONNECTOR

12.4: srf hom diagnostics: experimental results and future plans

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