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

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

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

Page 4 Status of the RFQ (i.e. the 4-vane cold model) UKNF Meeting 3 rd October 2007Ajit Kurup Bead-pull E-Field Measurements Ø 6mm dielectric bead

Page 5 Status of the RFQ (i.e. the 4-vane cold model) UKNF Meeting 3 rd October 2007Ajit Kurup Results Presented at PAC 2007 Frequency [MHz] Unloaded Q Predicted Measured after brazing ± ±50

Page 6 Status of the RFQ (i.e. the 4-vane cold model) UKNF Meeting 3 rd October 2007Ajit Kurup Improved Result f = MHz Q 0 = 6968

Page 7 Status of the RFQ (i.e. the 4-vane cold model) UKNF Meeting 3 rd October 2007Ajit Kurup New End Flange and Inserts HUB SPACER GUIDE CONE FINGERS FINGER HUB

Page 8 Status of the RFQ (i.e. the 4-vane cold model) UKNF Meeting 3 rd October 2007Ajit Kurup 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.