Magnetics Program Highlights VLT Conference Call September 13, 2000 presented by J.V. Minervini MIT Plasma Science and Fusion Center

Summary of successful testing of CS Model Coil and CS Insert Coil  World’s largest pulsed superconducting and Nb 3 Sn magnet successfully tested Superconducting Quadrupole Magnets for IFE  Progress made by LLNL and MIT in HCX prototype coil design and testing Successful acceptance test of LDX Floating Coil Outline

CSMC is Composed of 3 Coil Modules JA Outer Coil Module Schematic Assembly of CSMC and Support Structure US Inner Coil Module Coil Assembly in Test Facility CS Insert Coil (JA) + + =

I. CSMC test conditions A. DC operation 1. Confirmation of 13T at 4.5K and 5.3K 2. Critical properties determination 3. Joint resistance measurement B. AC loss measurement 1. Using resistive discharge at various currents and time constants 2. Using bi-polar field pulses 3. Using symmetric trapezoid field pulses C. Pulsed operation 1. Baseline scenarios to confirm 2K operating margin. 2. Determination of limiting ramp rates at T > 4.5K CSMC Was Extensively Tested

II. CS Insert test conditions A. DC operation 1. Confirmation of 13T operation point 2. Determination of critical properties (normal and reverse current) B. AC loss measurement 1. With and without transport current in the insert 2. Using resistive discharge at various current levels and time constants 3. Using bi-polar field pulses 4. Using symmetric trapezoid field pulses C. Pulsed operation 1. Stability measurement using pulsed inductive heater 2. Confirm 2K operating margin 3. Determine limiting ramp rates at T>4.5K D. Quench propagation measurement E. Cyclic operation to 10,003 cycles CS Insert Was Extensively Tested

Results of DC Measurements Joint Resistances were measured at 46 kA by electrical and calorimetry methods. Initial analysis of current sharing temperature shows conductor properties scale well from known strand, temperature and strain data.

Pulse Testing 0.6 T/s symmetric, trapezoidal ramp to 13T field in the CS insert. Coil was ramped as fast as 2 T/S to 13T. 13 T

Ramp rate Limitation Tests No anomalous Ramp Rate Limitation observed - quenched by  T due to AC Losses

Decrease in T cs of the CS Insert with number of cycles. Effect needs to be further studied. Superconducting Properties Affected by Cycling

1. Conductor properties Incoloy magnetization, further analysis of superconductors 2. Joint and Conductor losses Joint losses consistent, ac losses need signifcant analysis 3. Limiting ramp rate limited by ac loss heating, HETR3D simulation planned 4. Pulsed stability data reduction continues, HETR3D simulations planned 5. Quench propagation velocity, hot spot temperature analysis 6. Coil properties mechanical, thermal analysis On Going Data Analyses 2 Insert Coils Remain to be Tested in FY2001 Nb 3 Sn TF-type conductor Nb 3 Al TF-type conductor

LLNL HCX quad schematic (Racetrack Coils) Accelerating unit Focusing unit HCX layout HCX LLNL prototype design complete Designed field quality works well in physics simulations Prototype fabrication is underway Winding and assembly trials, and tooling development is in progress Most of the parts for prototype program are procured Developed a conceptual design of the HCX assemblies with 6 quads in one with interfaces with other HCX systems Racetrack Quads for IFE Development Status at LLNL

Quadrupole Magnets for IFE Development Status at MIT 3D model of HCX quad (one of four coils shown, Cos2  spacing) MIT is analysizing the Cos 2  mulitlayer coil designs of Advanced Magnet Lab. Inc. (AML) -Magnetic field quality, stress analysis -Manufacturing joints and lead arrangment Two single layer protoype HCX coils have been tested this summer at MIT -Both coils showed premature quenching at joints New conductor and coil layer is being fabricated by AML - MIT will test when ready this fall

LDX Floating Coil Successfully Tested in July F-Coil being inserted into MIT test dewar Removing mandrel from F-Coil after completion of final joint Tested to 5.66T at 2200 amperes