1. Status
of the
Front End Test Stand
April 2007

2. Infrastructure
R8 refurbished
Laser lab under construction
Vacuum system for first section delivered
Stands for accelerator ordered
Basic electronic equipment for first phase delivered

3. Ion source development
Extensive experimental program underway on the IS rig. Main goal is the reduction of the source emittance by roughly a factor of 3.
57 mm

4. Ion source – transversal density distribution as a function of extraction potential
5 kV Ext
5.5 kV Ext
6 kV Ext
6.5 kV Ext
7 kV Ext
8 kV Ext
9 kV Ext
11 kV Ext

5. LEBT- 1st vacuum vessel design

6. LEBT Universidad del Pais Vasco joined the collaboration =>
Initial beam distribution based on pepper-pot data
Universidad del Pais Vasco joined the collaboration =>
responsible for LEBT (in cooperation with Warwick) & beam dump
3D model of B-fields incorporated into simulations => slight increase in field strength required.
rms norm ~ 0.9 mm mrad
1% beam loss
At end of LEBT

7. RFQ cold model
The 4 quadrants of the 4 vane RFQ cold model (l=0.5 m) are machined.
The quality of the quadrants will be controlled by using a CMM and beat pull measurements will be performed before and after brazing.

8. First RF measurements on the unbrazed RFQ cold model
First tests of the cold model using new couplers showed a resonant frequency of ~ 323 MHz
A very good field flatness has been measured using the beat pull method

9. MEBT and Chopper MEBT & Chopper:
Transition from particle trajectory design to real design
Incorporation of pumping ports etc. into design and reoptimisation of beam dynamics
Hybrid quadrupoles:
The printed circuit electromagnet: A company near Newbury specialised in printed circuit boards manufacturing. In progress.
Daresbury Magnet Testing Group agreed to measure the PMQ in the next month. (Point by point measurement with a Hall probe).
Particle dynamics:
Comparison between CERN and RAL design (IS to end of DTL) showed slightly better results for RAL solution - simulations with higher current are planned.
Code benchmarking in progress

10. MEBT & Chopper – code benchmarking
Lattice: FETS Scheme A Codes: TraceWin/Partran, Trace3D, GPT
TraceWin/Partran
GPT

11. Pepper pot emittance measuring device
Tungsten screen
Copper block
Scintillator screen
H- Beamlets
Fast CCD Camera
H- Ion Beam
The grid head is mounted to the cooled rod.
Cooled feed through rod.
The linear shift mechanism mounted to the main flange.
Close up of the assembled grid head showing the quartz plate.
A pepper pot device mounted on a linear stage for correlated measurements of the transversal phase space along beam propagation will be available soon.
Adjustable camera mount.

12. Pepperpot data analyses test
Image width: 100mm
x-x’
y-y’
Camera res. = 49 microns/pixel Angle res. = 4.88 mrad

13. Laser tomography Motion controller Amplifiers and power supplies
Encoders
Rotary stage
Linear stage

14. Laser emittance R=477.5mm Arc length 500mm B = 0.522T Gap 136mm
Width 200mm
Deflection 60deg
max. beam size ~R=20mm
negative ions,
RG neutrals
At the position of photon
interaction can be detected
a max. beam diameter
of 40mm with +/-30mrad
(a matched ion beam has
app. 20mm and +/-20mrad).
photo detached
neutrals
deflected negative ions

15. space for piezo driven stages
Laser emittance
space for piezo driven stages
vacuum
vessel

16. Summary & outlook Very good progress on all fields
IS optimisation is a major physical challenge but first results are encouraging
RFQ cold model pre tests started
Infrastructure for first phase prepared
Good collaboration with Spanish partners