Prorenin anno 2008

For many years, prorenin has been considered to be nothing more than the inactive precursor of renin. Yet, its elevated levels in diabetic subjects with microvascular complications and its extrarenal production at various sites in the body suggest otherwise. This review discusses the origin, regulation, and enzymatic activity of prorenin, its role during renin inhibition, and the angiotensin-dependent and angiotensin-independent consequences of its binding to the recently discovered (pro)renin receptor. The review ends with the concept that prorenin rather than renin determines tissue angiotensin generation

Self-protected high-temperature superconducting demonstrator magnet for particle detectors

A high temperature superconducting (HTS) demonstration coil has been developed in the frame of the Experimental Physics department Research and Development program at CERN The magnet extends the recent experimental demonstration of aluminium-stabilised HTS conductors and supports the development of future large scale detector magnets. The HTS magnet has five turns and an open bore diameter of 230 mm. Up to 30 K, the coil was measured to be fully superconducting across four central turns at 4.4 kA, the maximum available current of existing power supply. The central magnetic field is 0.113 T, the peak field on the conductor is 1.2 T and the coil has a stored magnetic energy of 0.1 kJ. A 3D-printed aluminium alloy (Al10SiMg) cylinder acts both as a stabiliser and a mechanical support for the superconductor. The resistivity of Al10SiMg was measured at cryogenic temperatures, and has a residual resistivity ratio of approximately 2.5. The ability to solder ReBCO tapes (a stack of four REBCO tapes, 4 mm wide, Fujikura) to Al10SiMg stabiliser, electroplated with copper and tin, forming a coil, is demonstrated using tin-lead solder at 188 $^{∘}$C. The HTS magnet was proven to be stable when superconductivity was broken locally using a thin-film heater. Despite voids in the solder joint between HTS and stabiliser, no degradation of the magnet’s performance was observed after 12 thermal cycles and locally quenching the magnet. A numerical model of the transient behaviour of solenoid with partially shorted turns is developed and validated against measurements. Our work experimentally and numerically validates that using an aluminium alloy as a stabiliser for HTS tapes can result in a stable, lightweight and transparent magnet

Characteristics of Aluminium-Stabilized HTS Detector Magnet Cable at 4 K and 5 T

A high-temperature superconducting (HTS) cable for future particle detector magnets has been developed using a 99.3% pure aluminium alloy as a stabilizer for the HTS. This HTS conductor features a stack of four ReBCO tapes (4 mm wide, SuperOx) soldered to a tin-coated copper-clad aluminium alloy cable profile using tin–lead solder at 188 °C. Here, we experimentally demonstrate that the cable withstands both thermal cycling between 4 K and room temperature and Lorentz forces induced by external magnetic field of 5 T when the HTS cable is driven by 4.5 kA. The HTS cable has no visual damage and no change in the critical current after being exposed multiple times to these extreme conditions. We show that since the phase transition of ReBCO is gradual, an aluminium alloy with low residual resistivity ratio (RRR) can be used as a stabilizer, which brings many advantages, such as a better availability compared to pure aluminium and a mechanically stronger cable

HTS Detector Magnet Demonstrator Based on a 3D-Printed Partially-Insulated Support Cylinder

In this work, we extend the experimental demonstration of partially-insulated, ultra-radiation transparent detector magnet technology based on a 3D-printed aluminium alloy support structure containing 10% of silicon. This demonstrator magnet has a bore diameter of 390 mm, effective wall thickness of 3.7 mm, and it has 15 turns corresponding to 19 meters of HTS conductor. The HTS conductor of the magnet consists of a stack of four ReBCO tapes with a width of 4 mm. We measured the magnet to be fully superconducting at 4.2 K with an operating current of 4.5 kA. A time constant of the magnetic field delay to a current step measured was 83 s. This detector magnet technology may be used in future particle detector magnets, such as the AMS-100 solenoid, where one of the key design requirement is a passive self-protection by partial-insulation which ensures continuous operation and stable magnetic field even with a locally damaged conductor

Annual Report 2023 and Phase-I Closeout

This report summarises the activities of the CERN strategic R&D programme on technologies for future experiments during the year 2023, and highlights the achievements of the programme during its first phase 2020-2023