Allan DeMello

Design and Analysis of the Quench Protection System for the MICE Coupling Coils

Two identical MICE coupling coils have the largest diameter and stored energy, at 13 MJ each, of all coils in the Muon Ionization Cooling Experiment (MICE). The coils have an inner diameter of 1.5 m and radial and axial builds of 102.5 and 285 mm, respectively. The coils contain approximately 15 936 turns and are wound with a single rectangular NbTi strand with a copper-to-superconductor ratio of 3.9:1. Each coil is conduction cooled using three cryocoolers, which maintain an operating temperature at about 4.5 K. Each coil is powered through a pair of series-connected copper and 500 A HTS current leads. The quench protection analyses described here show that subdividing the winding into four or more, cold-diode-protected subsections maintain hot spot temperatures below 150 K and internal winding voltages below 300 V. The superconducting subdivision interconnect loops are protected by heat sinking them to the aluminum winding housing. Stabilizing the coil leads from the winding to HTS current leads minimizes the likelihood of lead quench. The first of three coils will be tested at Fermi Lab and the final two coils will be installed in MICE at Rutherford Laboratory.

Thermal and Mechanical Performance of the First MICE Coupling Coil and the Fermilab Solenoid Test Facility

The first coupling coil for the Muon Ionization Cooling Experiment (MICE) has been tested in a conduction-cooled environment at the Solenoid Test Facility at Fermilab. An overview of the thermal and mechanical performance of the magnet and the test stand during cool-down and power testing of the magnet is presented.

RF Cavity Processing and Testing Plan for MICE

Fabrication status of the MICE RF cavities will be described. Design of a single-cavity vessel to test the cavities will be discussed, along with the plans for processing and testing the cavities.

The Cooling and Safety Design of a Pair of Binary Leads for the MICE Coupling Magnets

The key to being able to operate the superconducting solenoids in the Muon Ionization Cooling Experiment (MICE) using cryocoolers running at around 4.2 K is the application of high temperature superconducting (HTS) leads. Because the MICE magnets are not shielded, all of them will have a stray magnetic field in the region where the coolers and the HTS leads are located. The behavior of the HTS leads depends strongly on the HTS material used for the leads, the magnetic field and their warm end temperature. A pair of binary leads consisting of copper leads and HTS leads made from oriented multiple strands of BSCCO wires will be used for electrical transfer of the MICE coupling magnet for the purpose of reducing the heat leak through the leads to 4.2 K region. This paper mainly discusses the detailed design of the HTS leads and their cooling. Protection for the HTS leads during a power failure is discussed as well.