1. (i.e. the 4-vane cold model)
Status of the RFQ
(i.e. the 4-vane cold model)
Ajit Kurup
UKNF Meeting
3rd October 2007

2. Introduction 4-vane RFQ cold model is now brazed.
First RF measurements (done by Aaron Cheng) and comparison with simulations were presented at PAC 2007.
Investigate effect of the end flanges (i.e. influence capacitance at ends of the vanes and inductance at in the cutback region)
Ajit Kurup
UKNF Meeting 3rd October 2007

3. Previously
Ajit Kurup
UKNF Meeting 3rd October 2007

4. Bead-pull E-Field Measurements
Ø6mm dielectric bead
Ajit Kurup
UKNF Meeting 3rd October 2007

5. Results Presented at PAC 2007
Frequency [MHz]
Unloaded Q
Predicted
319.7
9300
Measured after brazing
±0.001
5616±50
Ajit Kurup
UKNF Meeting 3rd October 2007

6. Improved Result f = 318.462MHz Q0 = 6968 Ajit Kurup
UKNF Meeting 3rd October 2007

7. New End Flange and Inserts
GUIDE
CONE
HUB
SPACER
FINGER HUB
FINGERS
Ajit Kurup
UKNF Meeting 3rd October 2007

8. Plan
Improve rf contact in new end flange parts (finger strips, garter spring).
Long list of measurements to do using new end flange and inserts.
Get a new electrical engineer.
Look at rf coupling for 4m RFQ.
Modulation of electrodes.
Beam dynamics simulations.
Ajit Kurup
UKNF Meeting 3rd October 2007