HALO-1kT – Helium And Lead Observatory for Supernova Neutrinos with High Sensitivity to $\nu_e$.

Neutrinos from a CC supernova will shed light on astro- and particle physics processes that leave different signatures on the ν \nu / ν¯ \bar\nu fluences. Existing detectors are most sensitive to ν¯e \bar\nu_e , so a lead-based detector with high νe \nu_e sensitivity would improve the characterization of the neutrino emission.

HALO-1kT, will be located at LNGS, and use 1kt of lead, instrumented with 3 ^3 He neutron counters. 208Pb(νe,e−)208Bi∗ ^{208}Pb(\nu_e,e^-)^{208}Bi^* reactions emit one or two neutrons that thermalize and are captured by 3 ^3 He. The ratio of 1n to 2n events is sensitive to the neutrino temperature and spectrum. Comparing the HALO-1kT signal with a ν¯e \bar{\nu}_e detector signal may resolve the neutrino mass hierarchy. HALO-1kT will participate in SNEWS.

HALO-1kT is in design and development. Activities include simulations for optimizing the geometry, development of low background neutron counters and modeling of the physics signal. A final design is expected by the end of 2018.