Development, Integration, and Test of the MACQU Demo Coil Toward MADMAX Quench Analysis

The MADMAX project aims at detecting axion dark matter in the mass range of 100 μeV. To facilitate axion to photon conversion with detectable rate a superconducting dipole magnet with a large bore is needed. The MADMAX dipole magnet has to generate ~9 T in a 1.35 m aperture over ~1.3 m in length. A key challenge for a magnet made of a cable in-conduit conductor (CICC), operating at 1.8 K with an indirect bath cooling is the quench detection. In order to validate feasibility, a mock-up coil with a quench behavior scalable to MADMAX was designed and produced. This mock-up was used to benchmark numerical simulations of the quench in the THEA code. The paper gives an overview of the technicaldetails of the MACQU test coil. The conductor, the magnet, the busbar and the supporting and cryogenic systems were designed at CEA. The cable was manufactured in China at the Chang Tong INC from WST Nb-Ti strands, the insertion and compaction was achieved in the ASIPP institute with a copper profile from Aurubis. The winding of the coil and the busbar pre-forming were performed at Bilfinger Noell as well as the assembly of the supporting structure and the thermal shield. The magnet was integrated in the JT60 test station at CEA Saclay and extensively tested

A polarized fast radio burst at low Galactic latitude

We report on the discovery of a new fast radio burst (FRB), FRB 150215, with the Parkes radio telescope on 2015 February 15. The burst was detected in real time with a dispersion measure (DM) of 1105.6 ± 0.8 pc cm-3, a pulse duration of 2.8+1.2-0.5 ms, and a measured peak flux density assuming that the burst was at beam centre of 0.7+0.2-0.1 Jy. The FRB originated at a Galactic longitude and latitude of 24.66°, 5.28° and 25° away from the Galactic Center. The burst was found to be 43 ± 5 per cent linearly polarized with a rotation measure (RM) in the range -9 < RM < 12 radm-2 (95 per cent confidence level), consistent with zero. The burst was followed up with 11 telescopes to search for radio, optical, X-ray, γ -ray and neutrino emission. Neither transient nor variable emission was found to be associated with the burst and no repeat pulses have been observed in 17.25 h of observing. The sightline to the burst is close to the Galactic plane and the observed physical properties of FRB 150215 demonstrate the existence of sight lines of anomalously low RM for a given electron column density. The Galactic RM foreground may approach a null value due to magnetic field reversals along the line of sight, a decreased total electron column density from the Milky Way, or some combination of these effects. A lower Galactic DM contribution might explain why this burst was detectable whereas previous searches at low latitude have had lower detection rates than those out of the plane