1. Challenges, Progress and Plans of SRF CH-Structures
Holger J. Podlech
Institute for Applied Physics (IAP)
University of Frankfurt
TTC Meeting
Jefferson Lab
November 5th-8th 2012

2. CH-Structures Crossbar H-Mode-Structure H211-Mode
Efficient DTL-structures for the low and
medium energy range
KONUS or EQUUS Layout

3. First CH-Prototype
f=360 MHz
b=0.1
Ueff=5.5 MV

5. Pick-up
Forwarded
Piezo signal
Horizontal Test

6. Learning Lessons From the First Prototype
Little space between stems for tuner and power coupler
 change orientation
New dynamic tuner without additional longitudinal space requirements
Poor preparation possibilities (only on-axis)  new cleaning flanges
Long end cells for field enhancement (additional drift)  sloped end stems

7. 325 MHz CH-Cavity Static Tuners Bellow Tuner Power Coupler
0.1545
Frequency (MHz)
Cells 7
Length bl-def (mm)
505
Diameter (mm)
348
Ea (MV/m) 5
Ep/Ea
5.1
Bp/Ea [mT/(MV/m)] 13
G (W) 64
Ra/Q0 (W)
1248
RaRs (W2)
80000
Power Coupler
Helium Vessel

8. 325 MHz CH-Prototype

9. Optimization of the Geometry of Superconducting CH-Cavities
Cost, Construction Time, Fabrication Inaccuracies
Arrived in Frankfurt
October 31st

10. 325 MHz CH-Cavity: First Measurements

11. 325 MHz Cavity: Static Tuners
Design Position
Deviation from Design frequency:
500 kHz < 0.2%

12. Strategy to Hit the Operation Frequency
Fabrication inaccuracy (Δf = 0.5 MHz)
Thermal shrinkage (Δf ≈ +400 kHz)
Pressure sensitivity (Δf ≈ +200 kHz)
Surface preparation (Δf = 6 kHz/mm)
Microphonics (Δf = ? Hz)
Lorentz Force Detuning (Δf = ? Hz)
End cell offset 10 mm (Δf ≈ ±1 MHz)
Static tuners (Δf ≈ +1.3 MHz, -2.2 MHz)
Surface preparation (Δf = 6 kHz/mm)
Slow bellow tuners (Δf ≈ ±250 kHz)
Fast bellow tuner (Δf ≈ ± 1000 Hz)

13. The MYRRHA Project Multi Purpose HYbrid Research Reactor for High Tech Applications
Struckturen durchgehen
Warum normalleitend / supraleitend
CH-Design
Solenoid-Design
Ein Kryomodul

14. The 17 MeV MYRRHA Injector
sc CH-4
sc CH-3
sc CH-2
sc CH-1
Parameter
Unit
Value
Frequency
MHz
176.1
Cells
---
7-10
L tot mm
Ueff MV Ea
MV/m
R/Q W
Struckturen durchgehen
Warum normalleitend / supraleitend
CH-Design
Solenoid-Design
Ein Kryomodul

15. Future GSI/FAIR Injector Complex
Parameter
Unit
Mass/ Charge 6
Frequency
MHz
Max. beam current mA 1
Injection energy
AMeV
1.4
Output energy
3.5 – 7.5
Output energy spread
AkeV
± 3
Length of acceleration m
12.7
Sc CH-cavities 9
Sc solenoids 7

16. cw SHE-Linac Demonstrator
Parameter
Unit
CH-1
Beta
0.059
Frequency
MHz
Gap number 15
Total length mm
687
Cavity diameter
409
Cell length
40.82
Aperture 20 Ua MV
3.369
Energy gain
MeV
2.97
Accelerating gradient
MV/ m
5.1
Ep/ Ea
6.4
Bp/ Ea
mT/ (MV/m)
5.4
R/ Q Ω
3320
Static tuner 9
Dynamic bellow tuner 3
Helium vessel
Coupler flange
Pickup flange
Inclined
end stem
Tuner flange
Preparation
flange

17. Cryo Module cw SHE-Linac Demonstrator

18. Setup for Beam Tests at GSI
217 MHz Demonstrator
108.4 MHz RFQ
108.4 MHz IH-Cavity

19. Thank you