C. Rode

Energy Doubler Satellite Refrigerator Magnet Cooling System

The Fermi National Accelerator Laboratory superconducting accelerator (energy doubler) is a 6-km-long magnet ring consisting of 1000 magnets ultimately to be cooled by 24 “satellite” refrigerators. At present there are three operating refrigerators and several strings of magnets, the longest being 0.15 km, through which a proton beam of 1.25 x 1013 protons per pulse has been transported.

The Cryostat for the SSC 6 T Magnet Option

A design has been developed for an SSC 6T option dipole magnet cryostat. The design criteria that defines the basic parameters and performance requirements are discussed. Details of the single phase assembly, suspension, insulation, thermal shields, vacuum vessels and interconnections are presented. Results of the experimental program in support of the design effort are discussed.

Energy Doubler Refrigeration System

The design concept of a central liquefier supplying satellite stations as well as failure nudes will be discussed. Performance data will also be presented.

Quasi-Optimal Algorithms for the Control Loops of the Fermilab Energy Saver Satellite Refrigerator

The Cryogenic System of the Satellite Refrigerator for the Energy Saver Accelerator Ring comprises 12 interrelated closed loops and several open loops. A quasi-optimal algorithm to control the Cryogenic System, under different modes operation, is described. The constraints imposed to define these algorithms and the process followed to characterize the functional parameters are described. A report on the results obtained with the algorithms in a test facility will be presented.

Operation of Superconducting Magnets in Fermilab Extracted Beams

We discuss the design and layout of the refrigeration, transfer, and magnet systems. We also present data on heat leaks and beam losses.

Operation of Multiple Superconducting Energy Doubler Magnets in Series

In order to understand the operational characteristics of the Energy Doubler, we have started a series of experiments designed to be a practical test of running superconducting accelerator magnets in series. We describe two separate tests in which we have powered two Energy Doubler dipoles in series. Of particular interest are the static losses of the cryostats and the behavior of the coils and cryostats during quenches. The results of the tests show that Energy Doubler magnets can be safely operated near their short sample limit, and that the various safety devices used are adequate to protect the coils and the cryostats from damage.

Operation of Large Cryogenic Systems

This report is based on the past 12 years of experiments on R and D and operation of the 27 kW Fermilab Tevatron Cryogenic System. In general the comments are applicable for all helium plants larger than 1000W (400 l/hr) and non mass-produced nitrogen plants larger than 50 tons per day. 14 refs., 3 figs., 1 tab.

The Multiple Magnet Test Program

A test facility has been constructed at the B12 location of the Fermilab main accelerator in order to test superconducting Doubler magnet strings under conditions similar to their final operating conditions while minimizing the interference to the ongoing 400 GeV program. Tests on the cryogenic, magnet and magnet power supply systems have been performed. In addition, a quench protection system has been tested that protects the magnets from damage due to a quench up to the full operating current of the Doubler.

The SSC cryogenic system

The design of the 4.5 K primary cooling system and higher temperature shield cooling systems for the SSC are described. Typical flow diagrams for the magnet piping systems are presented. Estimated heat loads are given. The systems have been designed to accomodate the great distances, 90 km and up, over which the load will be distributed. Provision has been made for cooldown, warmup, quench recovery and magnet replacement, as well as for steady-state operation.

The ironless cos θ magnet option for the SSC

The Fermilab design of a 5 T, 5 cm aperture superconducting dipole is described, that attempts to integrate essential cryogenic details with a low cold mass, low heat leak magnet containing a coil surrounded by aluminum collars. Operating characteristics of coils made with aluminum collars are presented along with harmonic data obtained from 1 meter long 5 cm aperture collared coils. A summary of results obtained from cold tests of a 7.6 cm aperture, 6 m long aluminum collared coil in an iron vacuum vessel cryostat are reviewed. Results from the measurement of heat leak to 4.5K, 10K, and 80K are discussed for a 12 m prototype cryostat. Calculations are summarized for passively correcting the persistent current sextupole fields.