1. RFQ Matcher

2. What am I doing this time?! Concerned that modulations and matcher affect field flatness and frequency These are very small features How much do they affect bulk 4m RFQ?

3. Matcher Geometry Plane vanes Matcher On

4. Matcher E-field Plane vanes Matcher On

5. First three modes’ B-fields

6. First three modes’ E-fields

7. Mode Frequencies: Matcher On/Off

8. Cold Model Field Flatness

9. Four Metre RFQ Field Flatness

10. Variation of Finger Length 10mm diameter fingers of varying length 15mm in x and y from beam axis

11. Variation of Finger Position 10mm diameter, 80mm long fingers Vary finger distance from beam axis

12. Conclusion Matcher does make large scale differences Modulations will do the same Need to stop using plane-vane models End fingers help, but need to pay attention to field flatness Leads to complicated tuning!