116th ATF2 weekly meeting

International phone/webex meeting

Update on Shintake background simulation, Marc Verderi (LLR - Ecole polytechnique) , Hayg Guler

M.Verderi reported the simulation status. Two models of Shintake detector and beam dump were explicitly shown as major updates in the GEANT4-standalone simulation. Implementation of models is simple to use a macro file. The 30 MeV photons and photons with exponentially decaying spectrum were simulated as the signal photons and the bremmstrahlung photons, respectively. It was found that 10K dumped electrons produced one energy deposit in Shintake detector ( remember one bunch consisting of 10¹⁰ electrons which are dumped) .

Next tasks are simulation of BDSIM to the end line, merge the standalone simulation in BDSIM and bias the simulation for efficiency.

Q to Shintake monitor group : when will be new detector installed ?

A : It was just constructed. Next it will be tested. So, ii takes time for the installation.

Q : What is the new detector ?

A : It is a sampling calorimeter consisting of SUS and plastic counters, as Y.Yamaguchi reported at previous KEK site meeting. Anyway, we still use the old one in this fall run .

Q : Can we add factors as weights/bias in the simulator ?

A : Yes, it is our plan.

C : if you can know source points to reach Shintake monitor, you can simulate background from them.

Q : When will you come to KEK ?

A : We will arrive on 4th November to install new detectors .

Q : What is the status or any questions on geometries which we sent ?

A : While it is easy to prepare the standalone simulation, it is difficult to put detailed geometries in BDSIM.

C : You may ask Olivier Dadoun (LAL) for such implementation.

C/Q : Information of new instruments and a list of beam parameters will be useful for update of the simulation.

A : you can use scaled parameters from those which Sha sent.

Discussion on the commissioning

Number 5 klystron has trouble as T.Naito reported in previous ATF-local operation meeting, this Tuesday. Now, it seems to be repaired and under aging process. We will have beam on this evening. Since there are many changes at ATF, e.g. replacement of SLED tuners at LINAC, it may take a long time to tune the injection. We will have the ATF operation meeting (Webex) in this Friday, where we will discuss plans in next week.

Next, P.Bambade expressed his idea to call for colleagues to request shifts (machine time) for specific studies in order to organize the tasks efficiently.

C : In principle, I agree with you.

C : There is another way as we did previously, that is the program oriented commissioning since many foreign colleagues will be at ATF in November and December.

A : We have asked colleagues for visiting plans. Actual commissioning will be mixture of both ways with individual leaderships. One point is to organize a whole plan for November and December, while we will adjust them weekly on every Friday meetings.