Author:
Funakoshi Y.,Iida N.,Kikuchi M.,Mori T.,Natsui T.,Ohnishi Y.,Satoh M.,Seimiya Y.,Yoshimoto T.
Abstract
Abstract
At SuperKEKB, the maximum beam currents and the luminosity
could be limited by the beam injection in the near future. We
estimated requirements to the beam injection to achieve the next
target luminosity of 1 × 1035cm-2s-1. Two cases of β
y
* = 1 mm and
0.8 mm are considered. A simulation shows that we need to suppress
the emittance growth of the injecting positron beam in the beam
transport (BT) line down to its design value to meet the requirement
with β
y
* = 1 mm. In the case of β
y
* = 0.8 mm, we
need to improve dynamic aperture of LER in addition to the
suppression of the emittance growth. Efforts to improve the beam
quantity and quality in LINAC and in BT are summarized. The present
most serious problem concerning quality of the injecting beams is
emittance growth in the BT lines for both electron and positron
beams. Simulations and experiments show that the effects of ISR and
CSR in the BT lines cause a large horizontal emittance growth of the
electron beam. Several measures to suppress the emittance growth are
under considerations.
Subject
Mathematical Physics,Instrumentation