Paper | Title | Page |
---|---|---|
MOPC006 | Simulations and Experiments of Beam-Beam Effects in e+e- Storage Rings | 520 |
|
||
Funding: Work partially supported by the Department of Energy under Contract No. DE-AC02-76SF00515. Over the past decade, extensive simulations of beam-beam effects in positron-electron collliders, based on the particle-in-cell method, were developed to explain many complex experimental observations. Recently, such simulations were used to predict the future luminosity performance of e+e- colliders. Some predictions have been proven to be correct in the existing accelerators. In this paper, many effects such as dynamic beta, beam-beam limit, crossing angle, parasitic collisions, betatron spectrum, and beam-beam lifetime, will be reviewed from the viewpoints of both simulation and experiment. Whenever possible, direct comparisons between the predictions of the simulation and the corresponding experimental results will be provided. |
||
TPPP004 | Study of the Beam-Beam Effect for Crab Crossing in KEKB and Super KEKB | 925 |
|
||
Luminosity upgrade using crab cavities is planned at KEK-B factory (KEKB)in 2006. The crab crossing is expected to increase the beam-beam parameter >0.1, which is twice of present value, for KEKB. We discuss torelances of crab cavities and lattice to get the high beam-beam parameter. | ||
TPPP006 | Beam-Beam Simulation Study with Parasitic Crossing Effect at KEKB | 1033 |
|
||
KEKB is an asymmetric-energy, two-ring, electron-positron collider for B physics. Two beams collide at one interaction point with a finite crossing angle of 22 mrad. The bunch spacing has chosen to be 4 buckets (8 nsec) in most physics run of KEKB. While the shorter bunch spacing is necessary for a higher luminosity, the degradation of the specific luminosity by unknown reason is observed in 4 or 6 nsec spacing. In order to investigate whether parasitic crossing effect degrades a beam-beam performance, we have performed strong-strong beam-beam simulation with parasitic long-range beam-beam force. In this paper we present and discuss our simulation results. | ||
WPAP016 | High Brightness Electron Gun for X-Ray Source | 1488 |
|
||
A new electron-gun system is under development in order to increase X-ray from a rotating target. In commercial X-ray sources electron beams usually hit targets at the outer part. Owing to deformation by centrifugal force, there has been a limit on electron beam intensities. In order to overcome this difficulty, we adopted a new injection system which strikes inside of a ring-shape projection on a rotating target. It has an advantage in that heated-up points have supports back side against centrifugal force. This merit allows us to raise electron beam to give stronger X-rays. | ||
TPPP007 | Recent Progress at KEKB | 1045 |
|
||
We summarize the machine operation of KEKB during past one year. Progress for this period, causes of present performance limitations and future prospects are described. |