HARP

Home page of the Experiment: http://harp.web.cern.ch/harp/

The main motivation is twofold: to acquire adequate knowledge of pion yields for an optimal and quantitative design of the proton driver of the neutrino factory; and to improve substantially the calculation of the atmospheric neutrino flux which is needed for a refined interpretation of the evidence for neutrino oscillation from the study of atmospheric neutrinos in present and forthcoming experiments.
Stage 1 of the HARP experiment was recommended for approval by the SPSC on 1 December 1999, and was approved by the Research Board on 17 February 2000 as PS214, for data-taking in the East Area's T9 beam.
The HARP experiment comprises a large-acceptance charged-particle magnetic spectrometer of conventional design, located in the East Hall of the CERN PS and using the T9 tagged charged-particle beam. The crucial detector for low-energy secondaries is a cylindrical TPC inside a solenoid magnet which surrounds the target. Downstream, the TPC is complemented by a forward spectrometer with a large dipole magnet. The TPC, together with the forward spectrometer,ensures nearly full 4 p coverage for the momentum measurement of charged secondary particles.
Their identification is achieved by dE/Dx in the TPC, by time of flight (TOF), by a threshold Cherenkov detector, and by and electromagnetic calorimeter. A barrel of RPC surrounds the TPC and complements its particle identification capabilities. The experiment re-uses a lot of existing equipment, notably calorimeter modules from the CHORUS experiment and drift chambers from the NOMAD experiment.