Table 1 Parameters employed for the simulations of the damping ring [4] and collider arcs for the CDR parameters with 2 Interaction Points (IPs) [1] and the new baseline with 4 IPs [24]. Collider bunch length is shown as due to synchrotron radiation and including the effect of beamstrahlung (“BS”, in parentheses)
From: Mitigation of electron cloud effects in the FCC-ee collider
DR injection | DR extraction | Collider arc dipole (CDR, 2 IPs) | Collider arc dipole (4 IPs) | |
|---|---|---|---|---|
beam energy [GeV] | 1.54 | 1.54 | 45.6 | 45.6 |
bunches per train | 2 | 2 | 150 | 150 |
trains per beam | 8 | 8 | 1 | 1 |
r.m.s. bunch length [mm] | 3.4 | 2.1 | 3.5 | 4.32 |
(12.1 w. BS) | (15.2 w. BS) | |||
hor. r.m.s. beam size [μm] | 2200 | 98 | 120 | 207 |
vert. r.m.s. beam size [μm] | 2800 | 47 | 7 | 12.1 |
external magnetic field [T] | 1.8 | 1.8 | 0.01415 | 0.01415 |
bunch population \(N_{b}\) [1011] | 0.22 | 0.22 | 1.7 | 2.76 |
circumference C [km] | 0.242 | 0.242 | 97.76 | 91.2 |
momentum compaction | ||||
factor \(\alpha _{C}\) [10−4] | 15 | 15 | 0.148 | 0.285 |
synchrotron tune \(Q_{s}\) | 0.022 | 0.022 | 0.025 | 0.037 |
average beta function \(\beta _{y}\) [m] | 1.5 | 1.5 | 50 | 50 |
threshold density | ||||
\(\rho _{e}\) [1012 m−3] | 966.03 | 27.11 | 0.027 | 0.043 |