Beam Dynamics
 
  • ATF2

ATF2 is an international project to build and operate a test facility for the final focus system that is envisaged at ILC. The primary goal of this project is to establish the hardware and beam handling technologies pertaining to transverse focusing of the electron beam to nearly 40 nm. To realize it, there are several interesting subjects for our group in IHEP to study:

1. Tuning: tracking to the final target based on the existed tuning methods and looking for new tuning methods for tracking simulation.

2. Lattice: optimize the existed ATF2 lattice to get some better results.

3. Experiments: do some experiments on the ATF2 commissioning.

      There is a weekly ATF2 video meeting on 2:30 pm Wednesday at KEK; 1:30 pm at IHEP, 6:30am in France and 10:30pm Tuesday at SLAC (new time and place). We use the KEK WebEX system for connection. The main content covers the proceedings of ATF2 project, including the hardware system improvement and progress.

You can connect the KEK WebEX system by: https://kek.webex.com/mw0302l/mywebex/default.do?siteurl=kek-en&service=1.
The ATF2 weekly meeting minutes can be find on:
http://atf.kek.jp/collab/md/projects/project_frame.php?project_page=2

S.Bai, IHEP

 
  • Bunch Compressor

We continue our effort to find short bunch compressor for ILC. Based on Dr. E.S. Kims work, we find new parameters for the two stage bunch compressor. In these new parameters, the two stage RF sections for BC are all in the accelerating phase rather than decelerating phase to improve the accelerating efficiency. In Kims work, the RF section for the first BC is in the decelerating phase. The linac parameters are summarized in the following Table

Table 1. Main parameters of BC Linac section

 

Ein
/ GeV

Eout
/ GeV

z-in
/ mm

z-out
/ mm

-in
/ %

-out
/ %

rf
/ deg

R56
/ mm

L1

5

5.17

6

6

0.13

0.94

-60

-

BC1

5.17

5.17

6

1.68

0.94

0.94

-

-500

L2

5.17

13.44

1.68

1.68

0.94

2.9

-45

-

BC2

13.44

13.44

1.68

0.142

2.9

2.9

-

-60

The output parameter for the linac is the energy of 13.44 GeV, the horizontal normalized emittance of 8.58 mm mrad, the vertical normalized emittance of 0.02 mm mrad, and the energy spread of 2.9 %. Figure 1 is the output longitudinal phase space, the rms output bunch length is 0.142 mm.

fig1
 
Figure 1. The output longitudinal phase space
 
X. W. Zhu, IHEP