confidence, of spin-independent WIMP-nucleon cross sections above 8.1$\times$10$^{-8}$ pb for a WIMP mass of 55 GeV/c$^2$ [@z3fsr], and spin-dependent WIMP-neutron cross sections above 1.8$\times$10$^{-2}$ pb [@z3fsrsd]. The explanation of the DAMA annual modulation signal [@DAMA] by inelastic dark matter [@iDM] in a Maxwellian halo scattering on iodine was ruled out with 87% confidence [@z3inelastic]. Since then the instrument has undergone an upgrade with the replacement of the internal PMT array, the dominant source of background during the first science exposure. The addition of the veto detector will further improve the sensitivity of a second run of the experiment. These upgrades are as originally conceived, planned and scheduled prior to the first science run. As such, the necessity for a veto detector with high neutron rejection efficiency has been motivated by conservative nuclear recoil expectation levels from the first science run. Since considerably reduced second science run neutron induced nuclear recoil predictions have been successfully met following the internal PMT array replacement, the diagnostic capability and $\gamma$-ray tagging efficiency of the veto detector become increasingly significant.

By design, the veto detector itself contributes negligible additional background to the xenon target. All detector components have had their performance characterised extensively to maximise 