MERIT - The high intensity liquid mercury target experiment at the CERN PS

Abstract

Abstract-The MERIT experiment is a proof-of-principle test of a target system for high power proton beams to be used as front-end for a neutrino factory complex or a muon collider. The experiment took data in autumn 2007 with the fast extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of about 30 × 10 12 protons per pulse. The target system, based on a free mercury jet, allows to investigate the interseption of a 4-MW proton beam inside a 15-T magnetic field required to capture the low-energy secondary pions as the source of the required intense muon beams. Particle detectors have been installed around the target setup capable to measure the secondary particle flux out of the target and probe cavitation effects in the mercury jet when exited with a beam of variable intensity. With the analysis of the data ongoing, results will be presented here that demonstrate the validity of the liquid target concept.

Update on MOMENT Target Station Studies

“…At MOMENT, the liquid Hg-jet target of Neutrino Factory has been adapted, which was studied at MERIT, CERN [3,4]. High heat load and radioactivity will be produced at the target station because of high proton beam power of 15 MW but without the presence of shock-waves due to the application of a continuous (CW) proton linac [5].…”

Final results from IDS-NF study

“…The baseline target [16] consists of a liquid mercury jet inside a 20 T capture solenoid field (Figure 1, Right). The MERIT experiment [17] has provided a proof-of-principle of the mercury jet target. Increased radiation shielding surrounding the target had to be included to protect the target solenoid.…”

The Accelerator Complex from the International Design Study of the Neutrino Factory

“…The baseline target consists of a liquid mercury jet inside a 20 T capture solenoid field ( Figure 3). The MERIT experiment [13] has provided a proof-of-principle of the mercury jet target. …”

“…Neutrino oscillations can be studied from the decay of both µ + and µ − thereby improving sensitivity to CP violation. Neutrino oscillations in matter can be extracted from the appearance of ν µ in far detectors (the golden channel) [2]: , s i j = sin θ i j , c i j = cos θ i j , J ≡ c 13 sin 2θ 12 sin 2θ 23 sin 2θ 13 is the Jarlskog determinant and B ∓ ≡ |A ∓ ∆ 13 |, with A = √ 2G F n e the matter parameter and n e the electron number density.…”