• M.A. Green, D. Li, S.P. Virostek, M.S. Zisman
  LBNL, Berkeley, California
• Y. Ivanyushenkov
  CCLRC/RAL, Chilton, Didcot, Oxon
• W. Lau, A. E. White, H. Witte, S.Q. Yang
  OXFORDphysics, Oxford, Oxon

This report describes the progress on the coupling coil module for the international Muon Ionization Cooling Experiment (MICE). MICE consists of two cells of a SFOFO cooling channel that is similar to that studied in the level 2 study of a neutrino factory. The MICE RF coupling coil module consists of a superconducting solenoid, mounted around four cells of conventional 201.25 MHz closed RF cavities. This report discusses the progress that has been made on the superconducting coupling coil that is around the center of the RF coupling module. This report also describes the process one would use to cool the coupling coil using a single small 4 K cooler. The coupling magnet power system and quench protections system is also described.

• S.P. Virostek, D. Li
  LBNL, Berkeley, California

A finite element analysis has been carried out to characterize the RF, thermal and structural behavior of the prototype 201.25 MHz cavity for a muon ionization cooling channel. A single ANSYS model has been developed to perform all of the calculations in a multi-step process. The high-gradient closed-cell cavity is being designed and fabricated for the MUCOOL and MICE (international Muon Ionization Cooling Experiment) experiments. The 1200 mm diameter cavity is constructed of 6 mm thick copper sheet and incorporates a rounded pillbox-like profile with an open beam iris terminated by 420 mm diameter, 0.38 mm thick curved beryllium foils. Tuning is accomplished through elastic deformation of the cavity, and cooling is provided by external water passages. Details of the analysis methodology will be presented including a description of the ANSYS macro that computes the heat loads from the RF solution and applies them directly to the thermal model. The process and results of a calculation to determine the resulting frequency shift due to thermal and structural distortion of the cavity will be presented as well.

• D. Li, M.A. Green, S.P. Virostek, M.S. Zisman
  LBNL, Berkeley, California
• W. Lau, A. E. White, S.Q. Yang
  OXFORDphysics, Oxford, Oxon

We describe the progress on the design of the RF coupling coil (RFCC) module for the international Muon Ionization Cooling Experiment (MICE) at Rutherford Appleton Laboratory (RAL) in the UK. The MICE cooling channel design consists of two SFOFO cells that is similar to that of the US Study-II of a neutrino factory. The MICE RFCC module comprises a superconducting solenoid, mounted around four normal conducting 201.25-MHz RF cavities. Each cavity has a pair of thin curved beryllium windows to close the conventional open beam irises, so thatnecessitating separate power feeds for each of the four cavities has to be separately powered. The coil package that surrounds the RF cavities sits is mounted on a vacuum vessel. The RF vacuum is shared between the cavities and the vacuum vessel around the cavities such that. Therefore there is no differential pressure on the thin beryllium windows. This paper discusses the design progress of the RFCC module, the fabrication progress of a prototype 201.25-MHz cavity, and the superconducting coupling coil that will be cooled using a single, small 4 K cooler.

• R.A. Rimmer, S. Manning, R. Manus, H.L. Phillips, M. Stirbet, K. Worland, G. Wu
  Jefferson Lab, Newport News, Virginia
• R.A. Hafley, R.E. Martin, K.M. Taminger
  NASA Langley, Hampton, Virginia
• D. Li, R.A. MacGill, J.W.  Staples, S.P. Virostek, M.S. Zisman
  LBNL, Berkeley, California
• M. Reep, D.J. Summers
  UMiss, University, Mississippi

We describe the fabrication and assembly of the first prototype 201.25 MHz copper cavity for the muon ionization cooling experiment (MICE). This cavity was developed by the US MUCOOL collaboration and will be tested in the new Muon Test Area at Fermilab. We outline the component and subassembly fabrication steps and the various metal forming and joining methods used to produce the final cavity shape. These include spinning, brazing, TIG welding, electron beam welding, electron beam annealing and deep drawing. Assembly of the loop power coupler will also be described. Final acceptance test results are included. Some of the methods developed for this cavity are novel and offer significant cost savings compared to conventional construction methods.