RFQ Matcher
RFQ Matcher
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?
Matcher Geometry
Plane vanes Matcher On
Matcher E-field
Plane vanes Matcher On
First three modes’ B-fields
First three modes’ E-fields
Mode Frequencies: Matcher On/Off
Cold Model Field Flatness
Four Metre RFQ Field Flatness
Variation of Finger Length
10mm diameter fingers of varying length15mm in x and y from beam axis
Variation of Finger Position
10mm diameter, 80mm long fingersVary finger distance from beam axis
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!