R&D on long-strip MRPC
Multi-gap Resistive Plate Chamber (MRPC), which has excellent performance and relatively low cost per channel, is a good candidate for Time-of-Flight (TOF) system in modern high energy physics experiments. A new kind of MRPC, Long-strip MRPC (LMRPC) with 50 cm × 2.5 cm strips, was tested at GSI-FOPI with secondary beam. The resets show that this LMRPC prototype can achieve 60 to 70 ps σ time resolution and greater than 97% detecting efficiency. The cross talk between readout strips is less than 2%. The measured spatial resolution along the strips is about 0.36 cm σ.
The compressed baryonic matter experiment at FAIR
The Compressed Baryonic Matter (CBM) experiment will be one of the major scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the QCD phase diagram in the region of high baryon densities using high-energy nucleus-nucleus collisions. This includes the study of the equation-of-state of nuclear matter at high densities, and the search for the deconfinement and chiral phase transitions. The CBM detector is designed to measure both bulk observables with large acceptance and rare diagnostic probes such as charmed particles and vector mesons decaying into lepton pairs.
In-House Industrial Production of the Superconducting Conductor for the 43 T Hybrid Magnet of LNCMI-Grenoble
The hybrid magnet being built at LNCMI-Grenoble is based on the combination of resistive inserts, made up of Bitter and polyhelix coils, with a large bore superconducting outsert. It will produce, in the first step, an overall continuous magnetic field of 43 T in a 34 mm warm bore aperture. The superconducting coil will provide a nominal magnetic field of 8.5 T in a 1.1 m cold bore diameter. It relies on the novel development of an Nb-Ti/Cu Rutherford Cable On Conduit Conductor (RCOCC) cooled down to 1.8 K by a bath of superfluid helium pressurized at 1200 mbar. After a brief reminder of the specificity of hybrid magnets, namely the strong electromechanical coupling between resistive and superconducting coils, the main requirements of the RCOCC for efficient and reliable magnet operation are given. The test and validation phases prior to the industrial production of the RCOCC are reported, including the trial production of the ½ hard-drawn (H02 cold-worked) Cu-Ag 0.05% hollow stabilizer in continuous lengths of 325 m. The novelty of the RCOCC development concerns the assembly and the induction soft-soldering of the Rutherford cable on the Cu-Ag hollow stabilizer allowing a strict control of the interstrand contact resistance. Studies, developments, and the integration of the industrial production line at LNCMI-Grenoble are presented together with the result of the production of all RCOCC unit lengths.