International Linear Collider damping ring lattice design based on modified FODO arc cells

Abstract

In this paper, we present a new lattice design for the International Linear Collider (ILC) positron damping ring. The same lattice could be used also for the electron damping ring. This lattice is based on modified FODO arc cells, and has a freely tunable momentum compaction factor from 2 10 ÿ4 to 6 10 ÿ4 . In comparison with the baseline design which uses the theoretical minimum emittance arc cells, the advantages of this design are: freely tunable momentum compaction factor; smaller number of quadrupole and sextupole magnets; larger dynamic aperture; simplified layout and lower cost. The design principles and analysis techniques used in this paper to change the momentum compaction factor by a large amount while keeping a very low emittance and large dynamic aperture are very important for the ILC damping ring; at the same time it could be very useful for any high bunch density storage ring.

Ultra low vertical emittance at SLS through systematic and random optimization

“…It is stressed, however, that the emittance of the former result is obtained from beam size measurements while the latter result is estimated by using the Touschek lifetime. These values are comparable to those achieved in the present damping rings, and also to expectations from both future damping rings [1,9,10] and light sources [11]. However, not only a further reduction in the vertical emittance but also the means to control and maintain its value during operation is essential, especially for damping rings and colliders.…”

Investigation into the Uniformization of Proton Beams for FLASH Therapy

“…This ensures a suitable ratio at the nonlinear magnet, as shown in Figure 8, with the ratio at the first nonlinear magnet in the case being βx/βy = 66/3. Similarly, after passing through the first nonlinear magnet, the beam undergoes magnetic focusing through the FODO structure [29], increasing the βy value and decreasing the βx value. In this case, the ratio at the second nonlinear magnet is βy/βx = 70/0.12.…”

ILC 3.2 km damping ring design based on the FODO cell

“…In fact, the design study of the ILC 6 km damping ring started very early and went through intense competition [4][5][6][7][8][9][10][11][12][13]. Older versions of the ILC damping rings (OCS) [14] had used TME (theoretical minimum emittance) arc cells and had 6 arc sections.…”

“…Older versions of the ILC damping rings (OCS) [14] had used TME (theoretical minimum emittance) arc cells and had 6 arc sections. As early as 2005, the Chinese ILC group began using FODO (focusing and defocusing lens) cells in its design [13]. FODO structures have since replaced TME cells in the ILC damping design based on greater flexibility and large dynamic aperture.…”