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ESS-Bilbao Initiative Workshop. SNS Linac experience

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Page 1: ESS-Bilbao Initiative Workshop. SNS Linac experience

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� ! � �� " � � � � � � � �# # � � �$ �% � � "

Page 2: ESS-Bilbao Initiative Workshop. SNS Linac experience

2 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

���������������������������������

Dec. 15, 1999

March 2000

Sept. 2005

Page 3: ESS-Bilbao Initiative Workshop. SNS Linac experience

3 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

������������������ ��� ������

ORNL was responsible for integration, installation, commissioning and operation

Need a strong central team to take intellectual ownership of the accelerator

Page 4: ESS-Bilbao Initiative Workshop. SNS Linac experience

4 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

��� � ������������� ������� ����������������������� ��

2002 2003 2004 2005 2006

DTL Tanks 1-3

Front-End

DTL Tank 1

DTL/CCL

SCL

Ring

Target• �� � �& � " " �� � � � �� ' � � " � � �' � � � � �� � ( �� � ' � � � � #� � ) � & � � " � *� � � �� �

�" �� ' �( �� ' � � �� � �� # ) � � � � � � ��� � � � � �+ ,

• - � � � �" � ) � � � � � ��� � �� # � �� � � � � ' � � � � � � �' �� � ��& � �� � � � (

Page 5: ESS-Bilbao Initiative Workshop. SNS Linac experience

5 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

!� ���"������������#�������$�%���

• . / � ��� ' � � �� � ' � � � ( � ) � � ( � ��� � � � ( � � % � � ' � � � � � � � �� � � � � � � � �� / � �� & � �� �

1177 MW-hrs

480 MW-hrs

210 MW-hrs

127 MW-hrs

Pow

er (k

W)

Flue

nce

(MW

-hrs

)

Page 6: ESS-Bilbao Initiative Workshop. SNS Linac experience

6 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

!$&�

• � #� � 0 / � � � & 1 ( � / � �� ' 2 �� � �( � � �

• . / & #� � � � � � � � ( � 3 4 5 �� � � ( ' � �5

– *) � � �� ' � � �� � ) ,

Ion Source

Radio-Frequency Quadrupole

� �����

� ����� output

• 402.5 MHz

Page 7: ESS-Bilbao Initiative Workshop. SNS Linac experience

7 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

'������% ������

�����

� ���� output

• 6 Tanks

•210 drift tubes

•PM quadrupoles

• 2.5 MW klystrons (402.5 MHz), 1 per tank

• Experience with PM quadrupoles is fine

• Minimal beam loss / activation observed

• Robust structure

Page 8: ESS-Bilbao Initiative Workshop. SNS Linac experience

8 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

������ �����������

CCL is also a robust structure

- Issues with RF induced gate-valve failures

Some beam loss near the CCL entrance and exit

� ����

� ����� output

• 4 modules

• 48 segments

•5 MW klystrons (805 MHz), 1 per module

Page 9: ESS-Bilbao Initiative Workshop. SNS Linac experience

9 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

�% �����%���������

• �6 - � � � � �� � � � � � � � " #� " � � � � � � � � � 7

• �6 - � � � �� � #� � � � � � �� � �� � 8 � � & " ( / �� �

• % ) � � � � �� � ' � " � � �� � � � � / � � ( � � � � � � � ( � � � ' � �� � � � �� �� � � � � � �� �

• 9 � � � � � � � � :

• � � � �& � � � � *� � ;� < = �;� � � � ,

Medium beta – 0.61

High beta – 0.81

• SCL is flexible

• Issues with accessories (HOM couplers, piezo tuners, …)

• Unexpected low level of beam loss

Page 10: ESS-Bilbao Initiative Workshop. SNS Linac experience

10 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

��������������� ������������

• 6 � � � & ' � � ( �� � � � � �� ' � � � � � / � �# � " � � � � � � �

• > � �� �� � ( � � �' � � � � " � ( �/ " ββββ � � � � �� � � � � �� � � # � " �� �' � ββββ� � � � �� � / � ( � � � � � # � "

• 9 � � � � ��) � � � � � 3 ? 5 �� � � � � � � ' & ' � �� � � � ( � � �' �

• $ � � ( �� � �� ) #�� @ �� �� � � / � *� 4 � A � � � � � � 7 ,

0

2

4

6

8

10

12

14

16

18

1a 1c 2b 3a 3c 4b 5a 5c 6b 7a 7c 8b 9a 9c 10b

11a

11c

12b

12d

13b

13d

14b

14d

15b

15d

16b

16d

17b

17d

18b

18d

19b

19d

20b

20d

21b

21d

22b

22d

23b

23d

Cavity number

Eac

c (M

V/m

)

Aug_08 Nov_08

+ 25%design

0

2

4

6

8

10

12

14

16

18

1a 1c 2b 3a 3c 4b 5a 5c 6b 7a 7c 8b 9a 9c 10b

11a

11c

12b

12d

13b

13d

14b

14d

15b

15d

16b

16d

17b

17d

18b

18d

19b

19d

20b

20d

21b

21d

22b

22d

23b

23d

Cavity number

Eac

c (M

V/m

)

Aug_08 Nov_08

+ 25%design

Page 11: ESS-Bilbao Initiative Workshop. SNS Linac experience

11 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

��������������� �������������"

0

5

10

15

20

25

30

Medium beta cavity High beta cavity

Ave

rag

e E

acc

(MV

/m)

60 Hz collective limit

Individual limit or low rep rate collective limit (<20 Hz) inclosed loopIndividual limit or low rep rate collective limit (<20 Hz) inopen loop

0 10 20 30 40 50 60

Electron loading (EG heating, gas burst, quench)

Coupler Heating

HOM (1cavity disabled,

5 limited by large coupling)

Quench (hard, Eacc<10 MV/m))

Lorentz force detuning

No limits up to 22 MV/m

No. of cavities

• 6 � � � & � � � # � " � � � � ��" � �

– B �� �( � " �� � � � *" � C � ��" � �� ' #� � � ,

– 6 / � �� � � � � �� '

– 9 � � � �

• 6 ��� � �� � ��" � � � � 0 / �� � � � � � �� ' � � � � �� � � � �� ;5 � � � ) � � “�( � � �”�� ( �� �( / � ���" � �

• � � � � � � � � �� ' � � �� � " � � � � � � � �� ' � � " � � �' � �� � � � � � � � � � � � � � �' � � ( �� � �

Page 12: ESS-Bilbao Initiative Workshop. SNS Linac experience

12 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

SRF, ß=0.61, 33 cavities

1

from CCL

186 MeV

805 MHz, 0.55 MW klystron

805 MHz, 5 MW klystron

402.5 MHz, 2.5 MW klystron

86.8 MeV2.5 MeV

RFQ

(1)

DTL

(6)

CCL

(4)

�����!$�����%�

SRF, ß=0.81, 48 cavities1000 MeV

(81 total powered)

379 MeV

Warm Linac

SCL Linac

• Warm linac has 10 independently powered cavities• SCL has 81 independently powered cavities

� Many values to set w.r.t. the beam� A lot of Equipment to keep running!!!

DTL KlystronCCL Klystron

SCL Klystrons

Page 13: ESS-Bilbao Initiative Workshop. SNS Linac experience

13 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

( ��� ������������%������)��� ����%

• - � � ' � � � � � � � ( � � � � � *� � ' � / ( �� � �,� � ( � � � � ' & ' � �� � � � � � � � �� � � �� ' � � / � / � �

• ��� ' �� � � � � � > B � � � � � � � ( � " � �� / ( � � � �� '

Longitudinal phase advance through 1st DTL tank

TOF

Cha

nge

RF Cavity Phase

Different RF amplitudes

•Each cavity has a unique response (signature) to phase and amplitude scans

•Phase scan signature matching method uses model to match measurements and determine RF amplitude and phase setpoints

Page 14: ESS-Bilbao Initiative Workshop. SNS Linac experience

14 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

����������%������)��� ����%

• �" � ��δδδδββββ � � ( � " � ��� � ' � / ( �� � �� � � � � � ( � � � � � � � � � � � � &

– 6 � � � �( � � �> B ' � � � �� � A � � � & / � ( � � � � � ( � � > B � � �� � � � � �� ) � � � � � � � "

• $ � � � �/ � � � � � � � � �� ' # � � � � � � � � � & D

– �� � � � � � � � � & � " � �� / ( � # � � � " � @ �" / " � � #� ' � � ( �� �

– B �� @ �� ��� & �� � � > B � � � � � � � / �

RF Phase

Dow

nstr

eam

Pic

kup

TOF

Black = measured

Red = sine fit

Page 15: ESS-Bilbao Initiative Workshop. SNS Linac experience

15 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

�% �����%����������!$����% ���

• � ( � �� � � � ( � � � ( �� � � � # � � � � � � ' � �� � � ( ) � � � � � " > B � � / � � � � � ( � � � � � ' � � �� / � � � � � " > B � " � �� / ( � � � ( E � � � � � � � � � � � � � �� ��

– F � � � � � � � � ' � �� � � � ( �� � ( � � � �� � � �" �

– G / �� � �& � � � � � � #� " / � � � � � " > B � � � � ' � �

• �� � ( / � � � " � � & � � � �� ��� �� �

– % � � �6 - � � � � � � �� ) � ( � � � � ��� � � � #�� #�� � � �& � � ' � � " " � � �� > B � �� � �

Cavity:

Arrival Time:

Page 16: ESS-Bilbao Initiative Workshop. SNS Linac experience

16 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

* �����������������+����$�%���!��+�������� ���"

• �� � � � � � �� ' � � � ��� � � � � � �� � � � ( � � � � � � � / � � � ( ## � � � � � � � �� � " � �� / ( � � � � ( / � � ( # � � � #� � � � � � � �� � � � � & ) � � � � / � � � ( � � � � � �

• % � � #� / � � � � � � � & � � � � " � ) � � � � � ��� ( 1 � ��� � � � 2

• H � � � � � � � � � � � � � � � � �� ( �� � � � � � � � ��� ' ) � � ) � � �� 4 ( � ' � � � �

• $ ( � � � � � �� � � � � ' � �� � � � " � � �

-400

-300

-200

-100

0

100

200

300

1 7 13 19 25 31 37 43 49 55 61 67 73 79Cavity

Ph

ase

Ch

ang

e (d

eg)

-6

-4

-2

0

2

4

6

Mea

sure

d E

rro

r (de

g)

Phase ChangeMeasured Error

Page 17: ESS-Bilbao Initiative Workshop. SNS Linac experience

17 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

����*� �����,���%��� �����-.�/����

• 6 � � � � �� / �� � � � � � ' � / ( �� � �� � � � � � � � � � � � � � # � � � �6 - ��� � �

• F � �� ' � � � ��� ' � � � � �0 / � � � � � � � � � � # � " � � � � � � � � � � � � � � � � � � � � � � � � ( " � � � / � � � � � � " �� � � �

Consider this part of the scan

Page 18: ESS-Bilbao Initiative Workshop. SNS Linac experience

18 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

,���%��������*� ����

• 6 � � � � � � � � � � � � � � � " � � � / � � " � � #� " � � � � � � �

From Beam LossFrom Current Transmission

Page 19: ESS-Bilbao Initiative Workshop. SNS Linac experience

19 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

*�����������0������������������%������-.�/����

• �� � � � � � � � " � � � � � # � � � � � � � �� � / � � � " � � � � ' &

– � � � � / � � � � � � � � " � � ( � � � " � / � � � � *� � � � � � " ,

– � � � � / � � � � � � � " - � � *� � � �� ( �� � � ,

RMS Bunch Length

Halo tail ???

Page 20: ESS-Bilbao Initiative Workshop. SNS Linac experience

20 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

Total Expected Beam Loss & Hottest Expected Spot Meet Requirement

0 1 2 3 4 5 6 7 8Ptotal (W )

Fre

quen

cy

Expected Total Beam Loss100 Linacs, all errors

0 40 80 120 160 200W (M eV)

0

1

2

3

4

Bea

m L

oss

(W)

"Hot spots"

worst caseexpected loss

100 Linacs, all errors

Page 21: ESS-Bilbao Initiative Workshop. SNS Linac experience

21 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

�����)��� �������%��

0 20 40 60 80 100 120 140 160 180 200W (M eV )

0

5

10

15

20

25B

eam

Los

s (W

)

Pm inPavePm ax

10 Linacs , a ll errors+ m ism atch

DTL-CCL Transition CCL-SCL Transition

Page 22: ESS-Bilbao Initiative Workshop. SNS Linac experience

22 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

�����)��� ����������������

• � " � � � � " � � � � � � �� �� �� . % - E6 6 -

• $ � � � " � � � � � � ( �� � ( �� � � �6 -

Page 23: ESS-Bilbao Initiative Workshop. SNS Linac experience

23 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

������������������+�����

• ����������������

– � �� � ���� �� � ���� �� �� � � ����� �����

– ���� � � ������ �� � � � � �

• � ���� ������� � � � � � ���� �� ��� ����� ���� � �� � ��� �� �� ���� ������ �� �

• ! ���� ����� �� ���

– ���� � ���� � ���� �� ��"����� � ��� �! # $ ��%����� ���� ��& ' ���� �"� �(

– ) � � ����� ��� �� � ����� ������� �� � � �%�� � ����� �� ������ (

– ! �� �"� � ����� � � ��� ������ �� � � � �%�� � ����� � (

Prompt radiation due to beam loss Residual activation @ 1ft after ~ 48hIn

tegr

al B

LM d

ose

[Rad

]

Beam Loss monitor #

Page 24: ESS-Bilbao Initiative Workshop. SNS Linac experience

24 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

����)��� �����

• - � � � � � � � �� � � � �� ��(

• . �##� � � � � � ' � / ( �� � �� � � � � �� ) � � � � � � � � � � � �� �� � � �+

SCL Loss

0

50

100

150

200

SCL_Diag

:BLM

00

SCL_Diag

:BLM

01c

SCL_Diag

:BLM

02c

SCL_Diag

:BLM

03c

SCL_Diag

:BLM

04c

SCL_Diag

:BLM

05c

SCL_Diag

:BLM

06c

SCL_Diag

:BLM

07c

SCL_Diag

:BLM

08c

SCL_Diag

:BLM

09c

SCL_Diag

:BLM

10c

SCL_Diag

:BLM

11c

SCL_Diag

:BLM

13b

SCL_Diag

:BLM

14c

SCL_Diag

:BLM

16b

SCL_Diag

:BLM

17c

SCL_Diag

:BLM

19b

SCL_Diag

:BLM

20c

SCL_Diag

:BLM

22b

SCL_Diag

:BLM

23c

SCL_Diag

:BLM

25b

SCL_Diag

:BLM

26c

SCL_Diag

:BLM

28b

SCL_Diag

:BLM

29c

SCL_Diag

:BLM

31b

SCL_Diag

:BLM

32c

BLM

Rad

/C

1/24/08 300 kW6/17/08 - 480 kW12/15/08 - 650 kW

SCL Beam Loss

-50

0

50

100

150

200

250

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76

Warm Section

Rad

/C

10/13/2008

11/2/2008

11/24/2008

12/15/2008

1/6/2009

Beam Loss = dt� targetonpowerbeamsignallossbeam over 3 week run

Page 25: ESS-Bilbao Initiative Workshop. SNS Linac experience

25 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

����!����%���*��+������� �������!%��������

• I � �� � � � �� � �� � � � � � �� ' � � � � � � � � � � � " / � #� � � " � � � � " � � (

• �6 - � � �� � � � J � � � � � ' � #� �� � � ) � � " � � � � � � �� � � � � ( �� ' �

Linac Activation

05

101520253035

Dec-06

Mar-07

Jun-0

7Sep

-07Dec

-07Mar

-08Ju

n-08

Sep-08

Dec-08

Run

mre

m/h

r

0200400600800100012001400

MW

-hrs

<SCL>

charge1

3

1days after run3

Page 26: ESS-Bilbao Initiative Workshop. SNS Linac experience

26 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

• �6 - � � � �( / � �� � �� � � � � / ��( � / � 0 / �� � �& ( / � �� ' � � / � � & � ��

• 6 � � � � > �� ' � � �� � � � � / ��( / � �) � �� � �� " � � � � � ( &

Average SCL Residual Activation

01020304050607080

4/28

/200

7

8/6/

2007

11/1

4/20

07

2/22

/200

8

6/1/

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9/9/

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9

Run

Avg

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m S

ectio

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ctiv

atio

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Rem

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summer 07winter 08spring 08Fall 08

12 hr cooldown

Ring Foil Activation

0

100

200

300

400

500

600

4/28/2007

8/6/2007 11/14/2007

2/22/2008

6/1/2008 9/9/2008 12/18/2008

3/28/2009

Run

mR

em/h

r

summer 07Winter 08Summer 08Fall 08

Page 27: ESS-Bilbao Initiative Workshop. SNS Linac experience

27 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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• � � � � � � �� � � �� ' � ( ( � � � � �' � " " � �� � � � " � � � / � � " � � � �( � � �#& " � � � �� �� " � � � � � �

• �� � � & � � � � � � � � �� � � � " � � � � � / ' � / � � �6 - �) � �� � �� � �� � � �& " � � � / � � � � ��

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0.8

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Page 28: ESS-Bilbao Initiative Workshop. SNS Linac experience

28 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

0.0E+00

5.0E-05

1.0E-04

1.5E-04

2.0E-04

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SCL_Diag

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SCL_Diag

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SCL_Diag

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SCL_Diag

:ND24

SCL_Diag

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SCL_Diag

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LaserEnhanced loss

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Single electron laser stripping is used for profile measurements in the SCL

Page 29: ESS-Bilbao Initiative Workshop. SNS Linac experience

29 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

1 ������ �����)��� ������"���%����� �������������� ����

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Red= CCL4 vacuum

Others = SCL beam loss

~ 3 hours0

1

2

3

4

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6

7

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Bea

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Page 30: ESS-Bilbao Initiative Workshop. SNS Linac experience

30 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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• � / " � *� � � " ( �� � �� � � " � � ,�� � � � �� � ) � � � � � � � � � � � �� ;

SCL Beam Loss with Local Bumps

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0.5

1

1.5

2

2.5

SCL_Diag

:BLM20b

SCL_Diag

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SCL_Diag

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SCL_Diag

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SCL_Diag

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SCL_Diag

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SCL_Diag

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LM02

HEBT_Diag:B

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HEBT_Diag:B

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SCL Beam Loss with Local Bumps

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HEBT_Diag:B

LM09

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tive

loss

5 mm Cav on8 mm Cav on5 mm Cav off8 mm Cav off

Page 31: ESS-Bilbao Initiative Workshop. SNS Linac experience

31 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

Quad Strength Sensitivity

0

0.5

1

1.5

SCL_Diag

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04b

SCL_Diag

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SCL_Diag

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SCL_Diag

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SCL_Diag

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mal

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Progressively reduce quadrupole strength along the SCL

Page 32: ESS-Bilbao Initiative Workshop. SNS Linac experience

32 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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Page 33: ESS-Bilbao Initiative Workshop. SNS Linac experience

33 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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slow

Beam Position vs. mini-pulse

Page 34: ESS-Bilbao Initiative Workshop. SNS Linac experience

34 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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• � " � ' � ) �� ' � � �� �

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Page 35: ESS-Bilbao Initiative Workshop. SNS Linac experience

35 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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SNS: March 2000

It is possible

Page 36: ESS-Bilbao Initiative Workshop. SNS Linac experience

36 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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Few Watts Beam Loss

7 minutes

Ring Injection Loss correlated with RFQ resonance error

Page 37: ESS-Bilbao Initiative Workshop. SNS Linac experience

37 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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RTBT

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Injection Extraction

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Liquid Hg Target

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Page 38: ESS-Bilbao Initiative Workshop. SNS Linac experience

38 Managed by UT-Battellefor the U.S. Department of Energy Presentation_name

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