19 quadpole-systems were successfully installed for 7 through 9 January 2008, where 19 concrete base blocks have been installed for 10 through 20 December, 2007. Actually, 22 movers were installed in total, while 3 sextupoles and 3 dipoles were not installed because of the delay of magnets arrival and T-1 mounts, respectively. The three T-1s arrived at Narita airport last Sunday.
One of the quadrupoles was misplaced by 5cm along the beamline. Its baseplate will be modified.
Also, the dynamic range of FFTB mover was measured.
S.Bai updated her study which has been presented at the 5th ATF2 project meeting. This study estimates the maximum normalized integrated strengths ( unit in 1/m) for the ATF2 Final Doublet quadrupoles in the intermediate beta optics at the focal points of -54cm and +39cm for Honda monitor and carbon wire scanner, respectively, as well as IP. Especially, she found that the QD0 strength exceeds the maximum to focus the beam to a waist at the Honda monitor, for both the nominal beta function and enlarged values, that is -2.2 compared with the maximum of -1.5275.
Within this limit, the maximum distance is estimated to be -16cm from IP for the nominal beta function.
Reminding the motivation of this study, P.Bambade commented in his recent e-mail as follows; "In what we did we thought we should preserve as much as possible the basic optical features of the final focus (especially its internal symmetries), so we changed the input match and only adjusted the effective focal length of the FD (and readjusted the sextupoles) inside the final focus. In this way, the focal point at the Honda monitor (for any of the chosen beta*_y values) results from a configuration which is closely related to the nominal one. Hence all the work to move the waists in x and y by 54 cm longitudinally is done by the FD.
However, we believe that it must be possible to achieve similar conditions at the Honda monitor, within the existing ranges for QD and QF (hence not require to upgrade the QD power supply) if we also use some of the other quads within the final focus to help the FD, and then forget about keeping its properties. Probably for large beta*_y values with spot sizes matched to the resolution of the Honda monitor, the quality of the chromatic correction is less important anyway. However, would it be appealing to do that ? What would we really learn from tuning the beam at the displaced IP in such a condition, that could be extrapolated meaningfully to the nominal IP ?"
Special pole-side shims have been designed and are being prepared, because the FD magnets ( QD0 and QF1) have too large 12 pole components. It is expected that the 12 pole component will be 0.02% at r=1cm with the special shims. The shims will be fabricated in next 2 weeks, and they will be assembled in QD0 by 4 February 2008. The goal is to ship the FD magnets to LAPP by middle of March, 2008.
Cooling pipes for two sextupoles (SD0, SF1) will be shipped to LAPP. The old FFTB sextupoles will be shipped from KEK to LAPP soon. C.Spencer is working on administrative paper works for the shipment.
The three FF-sextupoles (old SLC magnets) will be refurbished and re-measured at SLAC and then shipped to KEK. The BPM mount will be prepared by Honda. The supports of these FF sextupoles magnets are being designed and will be made at SLAC.
Middle point of SF1-QF1 -14.2 mm
Middle point of SD0-QD0 -15.7 mm
IP -13.7 mm
Variation among these values may show the flatness of the floor. "
Before the shield-work, we would like to install QBPMs inside the magnets. This work can be done with portable crane of 1 ton.
A chain block crane will be set on the side-wall for works inside of the shield.
Status and installation/alignment method of the Shintake monitor were presented. It was reminded that the floor is not flat to be seriously considered . We continue to discuss on these issues.