Post on 20-May-2015
description
Overview of the latest SRF projects at the S-DALINAC*
Sven Sievers
TU DarmstadtInstitut für Kernphysik SFB 634
*Supported
by
the
DFG through
SFB 634
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Outline
•
Overview
of the
S-DALINAC
•
SRF at the
S-DALINAC
•
Vertical
bath
cryostat
•
Latest
measurements•
Piezo-Actor
•
Oscillating
Superleak
Transducers
•
Test in preparation•
RF power couplers
•
Outlook
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Overview of the S-DALINAC
Design values:
Max. energy:
130 MeVEnergy spread:
±10-4
Max. beam
current:
60 µADuty
cycle:
cw
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Overview of the S-DALINAC
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Overview of the S-DALINAC
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
SRF at the S-DALINAC
Material:
Frequency:
Mode:
Temperature:
Niob (RRR=300)
2.9975 GHz
TM010
,π
2 K
Length:
Eacc
:
Q0
:
Pdis
:
1 m
5 MV/m
3·109
4.2 W
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Vertical bath cryostat
Diameter:
35 cmDepth:
260 cm
Minimum required
LHe-level: 150 cmMaximum LHe-level:
190 cm
D = 35 cm
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Vertical bath cryostat
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Vertical bath cryostat
Operation characteristics•
Cooldown
300 K → 4 K
~ 1.5 h
•
Fill-up
to maximum
LHe
level
~ 2 h
•
Pump down to 35 mbar
/ 2 K
~ 2.5 h
•
Stand-by
losses
of cryostat
< 1 W
Current limitations•
No pressure
regulation
→ 35 mbar
kept
via cryostat
heating
•
Operation of vertical
cryostat
not
possible
while
linac
is
at 2 K→ Measurements
limited
to shut
downs
of the
S-DALINAC
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: Piezo Actor
Investigation of the
stroke
of a piezo-actor
@ 2 K to replace
magnetostricitive
elements
of fine tuning
system
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: Piezo Actor
Existing
tuning
system: Fine tuning
of cavity
with
magnetostrictive
elements
First measurements: Piezo Actor
Required
frequency
shift:1000 Hz
Resulting
cavity
deformation:2 µm
Required
stroke
of fine tuner:5 µm
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: Piezo Actor
Required
stroke
of fine tuner:
5 µm
Stroke
of piezo-actor
@ 300 K:
90 µmPredicted
stroke
@ 4 K*: 22.5 µm
Measurement
with
simplified
tuner
set-up
Measured
frequency
shift
@ 4 K in LHe:
~ 1100 HzResulting
stroke
of piezo-actor:
~ 5.5 µm
Measured
frequency
shift
@ 2 K in LHe:
~ 950 HzResulting
stroke
of piezo-actor:
~ 4,75 µm
*B. Sahu, G. Chowdhury, S. Ghosh, D. Kanjilal, D. Mathuria, R. Mehta, A. Pandey, P. Patra, A. Rai
and A. Roy: Use
of Piezo
Actuator
to Frequency
and Phase Lock a Superconducting
Quarter
Wave Resonator, Proc. of the
24th Linear Accelerator Conference
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: Piezo Actor
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: OSTs
Performance check of the
prototypes
of anOscillating
Superleak
Transducer
(OST)
for
quench
localisation
@ 2 K
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: OSTs
OSTs shall be used for thedetection
of quench
positions
of superconducting
cavities
The
quench
causes
a 2nd soundwave
in the
superfluid
LHe
that
can
be
detected
by
the
OSTs
The
location
of the
quench
isdetermined
by
triangulation
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
First measurements: OSTs
R –
Moment of the
heat
pulse1 –
Response of the
1st OST after
~ 2 ms
2 –
Response of the
2nd OST after
~ 4 ms
R
2
1
R 1 2
Test in preparation: RF power couplers
Characterisation
of new
power couplers
for
the
injector
upgrade
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Test in preparation: RF power couplers
Planed injector upgrade
•
Energy increase
in the
injectorsection
from
10 up to 14 MeV
•
Increase
in current
from60 μA to 150 –
250 μA
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Test in preparation: RF power couplers
Actual
power coupler: 500 W Qex = 3·106 - 1·1010
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
RF power couplers
transition
transition
beam
transfer
Design: TEMF
Fabrication: FZ Julich
M. Kunze, W. F. O. Müller
Actual
power coupler:
500 W Qex = 3·106 - 1·1010
Waveguide
coupler: 2 kW Qex = 5·106
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Outlook
•
Construction of Quench-Detection-Array
•
Development
of optical
inspection
setup
•
Further
investigations
of piezo-actors
•
Design of new
equipment
for
the
vertical
bath
cryostat(Bacholer/Master
thesises):
•
Measurement
of Q-value
via decay
time•
Design and construction
of T-Map-System
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Thank you for your attention
Institut für Kernphysik, TU Darmstadt
S. Sievers, U. Bonnes, J. Conrad, R. Eichhorn, F. Hug, M. Konrad,T. Kürzeder, N. Pietralla, A. Richter
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
04. Oktober 2010 | TU Darmstadt | Institut für Kernphysik | Sven Sievers
Closed loop for liquid Helium