Marzio Nessi: The New CERN Neutrino Facility
Again a talk which started with a rethorical question: Why a new facility at CERN ? “CERN should develop a neutrino program to pave the wa for a substantial european role in future LBL experiments”. This is an extract of the European strategy document. It is a very political statement, written in a cryptic fashion to allow flexibility in the implementation. It is a clear recognition of the european neutrino community.
In practice, we are confronted with two requests: the ones of Icarus and Nessie, which want to search for sterile neutrinos, and the expression of interest of a Laguna-LBNO consortium to demonstrate a new generation of neutrino detectors with a double phase of Liquid Argon TPC prototype. One should provide a neutrino beam at cern in the medium term (4 years) with two experimental facilities. This would satisfy the requests, and allow new ideas and detectors to come forward.
So one may come up with a layout of a primary beam from the SpS, a secondary target, and construct a new detector facility at 456m from the target, and a far detector facility at 1.6 km downstream. The main requirements of these facilities are the correct placements of near and far detectors, central neutrino energy of 2 GeV or less, the possibility of 4.5E19 POT per year for at least three years. There should be the possibility to have charged beams to calibrate the detector. In practice, CERN can provide a fast-extracted beam, with beam time structure similar to that of the CNGS beam. 2100 bunches with cycle every 6 seconds. 3.5×10^13 protons per cycle.
The speaker then discussed the details and layout of the proposed new facilities. I suggest interested readers to check the slides in the conference site, since they are well-done and informative, with lots of drawings. Later I will add some pictures here.
In summary, a well-conceived basic initial design of the CENF facility is available, together with investment costs estimates of 100M and a challenging plan. The schedule is very ambitious but it seems possible. All this, however, is meaningful only if the neutrino community is fully behind it and if it will strongly push toward the delivery of the facility. One has to start now. The real heavy load is on the detectors, which need to move very fast.
During question time, Carlo Rubbia mentioned that with such a facility and near and far detectors one could measure with muon neutrinos the same kind of disappearance phenomena of reactor neutrinos, to 1% or better in the matter of few months. He said that five standard deviations is a guarantee as a startup for this project.