Figure : Probe port modified CF16 blank flange Flange: Modified Kurt Lesker CF flange F0133X000N Vacuum seal: Viton or copper standard CF gasket Screws: M4 x 12 Stainless Steel Caphead Tuners The tuners are simple cylinders that fit into ports that are equi-spaced transversally in the RFQ. There are 8 tuner ports per major vane giving a total of 16 tuner ports per 1m length of RFQ. Each tuner will be water cooled and mounts to the RFQ via a stainless steel interim flange. This will protect the copper threads from stripping. Figure : Tuner port location on RFQ major vane The RFQ frequency has been modelled to be correct when the tuner faces are sitting flush with the inner surface of the quadrant radius. Once the RFQ has been assembled a bead pull test will determine whether the longitudinal fields are sufficiently flat. If required the tuners will be skimmed to make them protrude less, increasing the internal volume and driving the frequency down. Alternatively the interim flange will be skimmed making the tuner protrude into the cavity, reducing the internal volume and driving the frequency up. Figure : Section view of static tuner In addition one tuner port per 1m RFQ section will be fitted with a moveable tuner. The aim of the moveable tuner is to constantly move into and out of the RFQ in response to a signal from the feedback system. A loop protruding inside the RFQ will send a signal to the feedback system. The frequency will change due to volume changes caused by fluctuations in temperature. The movement is provided by a ZLTM50M (stepper motor) linear shift mechanism from VG Scienta. Figure : ZLTM50M linear shift from VG Scienta
Figure : Probe port modified CF16 blank flange Flange: Modified Kurt Lesker CF flange F0133X000N Vacuum seal: Viton or copper standard CF gasket Screws: M4 x 12 Stainless Steel Caphead Tuners The tuners are simple cylinders that fit into ports that are equi-spaced transversally in the RFQ. There are 8 tuner ports per major vane giving a total of 16 tuner ports per 1m length of RFQ. Each tuner will be water cooled and mounts to the RFQ via a stainless steel interim flange. This will protect the copper threads from stripping. Figure : Tuner port location on RFQ major vane The RFQ frequency has been modelled to be correct when the tuner faces are sitting flush with the inner surface of the quadrant radius. Once the RFQ has been assembled a bead pull test will determine whether the longitudinal fields are sufficiently flat. If required the tuners will be skimmed to make them protrude less, increasing the internal volume and driving the frequency down. Alternatively the interim flange will be skimmed making the tuner protrude into the cavity, reducing the internal volume and driving the frequency up. Figure : Section view of static tuner In addition one tuner port per 1m RFQ section will be fitted with a moveable tuner. The aim of the moveable tuner is to constantly move into and out of the RFQ in response to a signal from the feedback system. A loop protruding inside the RFQ will send a signal to the feedback system. The frequency will change due to volume changes caused by fluctuations in temperature. The movement is provided by a ZLTM50M (stepper motor) linear shift mechanism from VG Scienta. Figure : ZLTM50M linear shift from VG Scienta