Table 1.

Summary of LHC parameters for typical pp collision fills and corresponding expected sizes of the luminous region. Emittance and bunch length values (and the corresponding beam-spot sizes) refer to values expected at the start of a fill. The two values given for expected transverse and longitudinal beam-spot size in 2011 correspond to the two ${\mathit{\beta }}^{\ast }$ settings of 1.5 and 1.0 m. Measured average beam-spot parameters are presented in Table 3 (Sect. 4.4)

Year	2011	2012
Beam energy (TeV)	3.5	4.0
${\mathit{\beta }}^{\ast }$ (m)	1.5, 1.0	0.6
Normalised emittance ${\mathit{\epsilon }}_{\text{N}}$ ($\mathrm{\mu }$m rad)	2.5	2.5
Full crossing angle $\mathit{\varphi }$ ($\mathrm{\mu }$rad)	240	290
$4\mathit{\sigma }$ bunch length $T_z$ (ns)	1.20	1.25
Bunch length ${\mathit{\sigma }}_z$ (mm)	90	94
Expected transverse beam-spot size ${\mathit{\sigma }}_{x\mathcal{L}}$, ${\mathit{\sigma }}_{y\mathcal{L}}$ ($\mathrm{\mu }$m)	22, 18	13
Expected longitudinal beam-spot size ${\mathit{\sigma }}_{z\mathcal{L}}$ (mm)	60, 59	54