denis kostin, desy meeting. desy, november 9 , 2004 · denis kostin, desy mac meeting.desy,...

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

«VUV-FEL LINAC Accelerating Modules«VUV-FEL LINAC RF Power Couplers«VUV-FEL LINAC Cavities«Conclusion

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

ACC1 ACC2 ACC3 ACC4 ACC5RF-GUNBC2 BC3

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

CylindricalCylindricalTTF IIIMar. 20025ACC5Plane, WGCylindricalTTF IIJul. 20014ACC4Plane, WGCylindricalTTF IIFeb. 20033*ACC3

PlanarConical/Cyl.FNAL/TTF IIMar. 20001*ACC2Planar/CylConical/Cyl.FNAL/TTF IIIJan. 20042*ACC1

warm windowcold windowcoupler typeassembledmoduleposition

Five accelerating modules were installed into the TTF tunnel as a part of the VUV FEL LinacEach module has 8 superconducting cavities and RF power input couplers

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

TTF III Coupler

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

bias voltage, suppressing multipactingisolated inner conductor6 W70 K heat load

sufficient for safe operation and monitoring

diagnostic

0.5 W4 K heat load0.06 W2 K heat load

• safe operation• clean cavity assembly for high Eacc

two windows, TiN coated

pulsed: 500 µsec risetime,800 µsec flat top with beam

operation

1.3 GHzfrequency

adjustable( 106 - 107 )

fixed( 3*106 )

adjustable( 106 - 107 )

Coupling (Qext)

1.9 kW3.2 kW / 6.4 kW

3.2 kWAverage power

10 Hz5 Hz10 HzRepetition rate

150 kW250 kW / 500 kW

250 kWPeak power + control margin

XFELTESLA 9cell / upgradeTTF

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

FNAL coupler

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

module 70K shield 4K shield

cavitycold windowwarm window

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

À Total of 40 RF power couplers connected to the superconducting cavities in the VUV FEL linac, eight in a module.

À All couplers in the VUV FEL linac could be processed and operated up to the cavity performance limits.

À The parallel processing of 8 respectively 16 couplers at the modules is slower than that at the test stands or in the horizontal cryostat.

À RF power couplers were tested up to 1 MW of pulsed power at 1.3 ms pulse length 2 Hz at the test stand.

À RF power couplers operated ~270000 hours*coupler.À Last coupler design TTF III has simplified assembly as well as

better performance, conditioning time is shorter.À TTF III couplers are tested together with cavities at gradients of 35

MV/m (600 kW) 5 Hz without degradation of cavity or coupler.

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

[ ]mVPk

eL

PQQ

R

E

transt

Qtf

cavity

forloadsh

ACCload

fill

,

14 0

×=

=

−×=

−π

evaluated error margins for accelerating gradients in this test are about ±10..16%.

RF Power Calibration

Rsh/Q=1030Ω, Lcavity=1.035m, Qload=3×106, f0=1.3GHz, Pfor≈5kW,tfill=1300µs (for calibration, 500µs for flat-top (FT))

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

EP cavity

1 - Z54 2 - Z51 3 - D42 4 - D37 5 - AC72 6 - C47 7 - Z53 8 - AC690

5

10

15

20

25

30

35

FEMod

ule

2 3 .04 .2004

M o d u le 2*

EA

CC [M

V/m

]

Cavity

Cryostat tests: Vertical Horizontal Module (5Hz)

3dB att.

3dB WG power attenuator put before cavity 7 to lower the fieldemission and to use cavities 5,6 and 8 with higher gradients

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

1 - S31 2 - C44 3 - C46 4 - S36 5 - D2 6 - A18 7 - D1 8 - A170

5

10

15

20

25

30

35

Mod

ule

5 .11 .2002

M o d u le 1*

EA

CC [M

V/m

]

Cavity

Cryostat tests: Vertical Horizontal Module

2dB att.3dB att.1dB att.

WG power attenuators are installed before cavities 1, 2 and 6 to use other cavities with higher gradients

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

1 - D41 2 - S32 3 - S29 4 - S30 5 - AC58 6 - D40 7 - S28 8 - Z500

5

10

15

20

25

30

35

Mod

ule

BD, F

E

cav.

tune

r

M o d u le 3*

0 1 .10 .2004

EA

CC [M

V/m

]

Cavity

Cavity tests: Vertical (CW) Horizontal (10Hz) Module 3 (10Hz) Module 3* (5Hz)

During Module 3 disassembly couplers antennae touched cavity surface. Cavity 4: cavity tuner problem. Cavity 7: 6dB WG power attenuator installed.

6dB att.

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

1 - C48 2 - S34 3 - AC57 4 - AC56 5 - AC55 6 - AC59 7 - Z52 8 - AC640

5

10

15

20

25

30

35

Mod

ule

BD

BD

BDBD

M o d u le 4

0 1 .10 .2004

EA

CC [M

V/m

]

Cavity

Cavity tests: Vertical (CW) Horizontal (10Hz) Module 4 (1Hz) Module 4 (5Hz)

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

1 - AC62 2 - AC61 3 - AC65 4 - AC66 5 - AC79 6 - AC77 7 - AC63 8 - AC600

5

10

15

20

25

30

35

BDdark current src

M o d u le 5

0 1 .10 .2004

EA

CC [M

V/m

]

Cavity

Cavity tests: Vertical (CW) Horizontal (10Hz) Module 5 (1Hz) Module 5 (5Hz)

Cavity 6 is a source of a dark current of 200 nA (peak) at 25 MV/m. Radiation level measured at 1 m distance from module 5 dump side: 18 µSv/min.

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

1* 2* 3* 4 50

5

10

15

20

25E

AC

C [M

V/m

]

TESLA500 specs.

ModuleACC2 ACC1 ACC3 ACC4 ACC5

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

0

10 15 20 25 30

109

1010

Q0(E

A C C) @ 5 H z

M o d u le 1* M o d u le 3* M o d u le 4 M o d u le 5

QO

EA C C

[ M V / m ]

ACC2ACC3ACC4ACC5

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

1,0E+09

1,0E+10

1,0E+11

0 5 10 15 20 25 30 35 40Eacc [MV/m]

Q0

Low power testHigh power pulsed test 1HzHigh power pulsed test 5Hz

Accelerator RF test

Cavity AC72 1011

109

1010

Ú Same performance with beam as in previous low and high power tests without beam

Ú Very low cryogenic losses as in high power testsÚ Standard X-ray radiation measurement indicates no radiation

up to 35 MV/m

MAC Meeting. DESY, November 9th, 2004Denis Kostin, DESY

« All couplers in the VUV FEL linac could be processed and operated up to the cavity performance limits.

« The last two modules, 4 and 5, fulfill the TESLA500 specifications.

« ACC5 / module 5, tested at the repetition rate of 5 Hz was operating atthe accelerating gradient of 25.5 MV/m , 500 + 800 µs full length flat-toppulse and quality factor of 1×1010.

« ACC5: cavity 6 is a source of a dark current of 200 nA (peak) at 25 MV/m.

« ACC1: cavity 7 is a source of a dark current, up to 10 mGy/min measured on axis.

« All modules have functioned continuously during certain periods of time.

« The beam operation started with all modules.

« Cavity 5 (AC72, EP) tested in Module 2* / ACC1 reached 35 MV/m,confirmed with beam.