ATF2 SC-Q Meeting Minutes , November 18, 2009

ATF2 SC-Q Meeting

November 18 7:00- 8:00, Webex

Participants : Brett Parker, Andrew Marone, (BNL), Nobuhiro Kimura, Takayuki Tomaru, Nobuhiro Terunuma,Toshiaki Tauchi, Tatsuya Kume (KEK), Andrei Seryi, Glen White, Cherrill Spencer (SLAC), Eduardo Marin (CERN) etc.

ATF2 Upgrade Coil Design Status, Brett Parker (BNL)

file : ( Spread Sheet(xlsx) )

There is one change in the spread sheet which has been distributed on 14th November,2009. The maximum current of the main sextupole is 140A, after discussing with the hardware engineer,

Agenda at the face-to-face meeting at BNL, Brett Parker (BNL)

The agenda is not fixed. Topics will be a verification/review of design assumptions including laser view port of the cryostat and details on the spread sheet and discussion on the Qs from the TB, goals of stability, adjustment of magnetic fields and the responsibilities. B.Parker will contact to Monalisa group (Oxford university) for the laser port and vibration issues.

T.Tomaru (LBL/KEK) will have a presentation on the vibration issues with respect to the cryocooler system and Shintake monitor . N. Kimura (KEK) will have a presentation on the cryogenics system including the cost estimation.

The agenda will be ready before the meeting including contributions from domestic colleagues .

Q : We would like to ask for a webex connection at the summary session at least.
A : Yes, this time slot would works.
Q : Will you introduce who participate in the meeting ?
A : Yes, we will do by showing in the agenda.

Supplement of the proposal and discussion, T. Tauchi ( KEK)

file : ( pdf, 5 pages, 776KB )

First, T.Tauchi introduce the questions from the ATF Technical Board (TB) when the proposal was presented at the 7th TB meeting, 18 December 2008.

In order to reply the questions and updates since then, we would like to submit supplements to the TB and to have the presentation at the 8th TB meeting, 17th December, 2009. The contents were suggested as this. We would like to ask colleagues for writing notes in each subjects. The supplement would comprise the notes.

We discussed on the suggested contents.

In summary:

Since the questions are rather relevant to be answered and will be discussed at the face-to-face meeting, B. Parker and A. Seryi will be writers.
Author list should include all responsible persons and institutes. It must be relevant.
We would like to ask R.Tomas and E.Marin for writing a note on the ultra low beta studies for CLIC and upgrade of ILC including difficulty or limitation of realizing the pushed beta optics at present beam line.
B.Parker and N.Kimura will be writers on magnet and cryogenics systems, respectively, with well-defined responsibilities as possible as we can.
We would like to ask A.Jeremie for a note on the support system. The present movers can be used for alignment of the cryostat. Alignment issues should be consulted with KEK colleagues.
We would like to ask D.Urner for a note on vibration monitor of coils inside the cryostat by using laser interferometer.
Also, B.Parker and N.Kimura will be writers on schedule and timeline for construction and installation specifying assumptions or constraints if available. G. White will contribute the experimental plan after the installation.

Optimisation of ATF2 v4.1 with MAPCLASS, Eduardo Marin (CERN)

file : ( pdf, 8 pages, 296KB )

E.Marin reported optimization studies of the v4.1 optics with MAPCLASS as asked at previous meeting.

First, the beam size dependence was shown as a function of the normalized horizontal emittance ( from 2.5 to 6 um) at various higher orders, where the nominal IP beta functions are 4.0mm and 0.1mm in horizontal and vertical directions, respectively, the IP horizontal dispersion is -67.5nm and the nominal horizontal emittance is 6um. The IP beam sizes are &sigma_x=3.27um and &sigma_y=38.2nm.

Second, the sexupole strengths are tuned by optimizing the third order of &sigma_y . With the nominal beta functions and dispersion, The IP beam sizes are &sigma_x=4.5um and &sigma_y=35.9nm.

Third, both sextupole and quadrupole strengths are tuned by optimizing the fifth order of &sigma_y and &sigma_x . With the nominal beta functions, The IP beam sizes are &sigma_x=2.9um and &sigma_y=35.1nm. The dispersion is 10.0nm. The tuned strengths, i.e. currents are listed.

Finally, the both strengths and the IP beta functions are tuned at an intermediate stage towards the Ultra-Low &beta^* by optimizing the third order of &sigma_y and &sigma_x . The IP beam sizes are &sigma_x=3.21um and &sigma_y=33nm. The IP beta functions are &beta_x=4.0mm and &beta_y=0.08mm. The dispersion is 10.0nm.

Q : Did you include the higher order multipole components at the magnets?
A : No. We like to estimate these effects separately.
Q : Are the IP beam sizes RMS ?
A : Yes.
Q : Did you include the physical apertures of magnets, especially at QF1 ?
A : No.
Q : When will you come to KEK?
A : This Thursday, I will leave here and arrive at KEK, this Friday.
C : We will discuss more in details at KEK.

Next meeting will be a face-to-face one at BNL, 24th November,2009.
URL : http://ilcagenda.linearcollider.org/conferenceDisplay.py?confId=4291 .