A CLOSED-CYCLE REFRIGERATOR BASED PULSED MAGNET SYSTEM

2009 ◽  
Vol 23 (12n13) ◽  
pp. 3024-3028
Author(s):  
O. V. S. N. MURTHY ◽  
V. VENKATARAMAN
Keyword(s):  
Low Cost ◽  
Quantum Hall ◽  
Superconducting Magnet ◽  
Closed Cycle ◽  
Magnet System ◽  
Pulsed Magnet ◽  
Parallel Conduction ◽  
Efficient Heat Transfer ◽  
Lock In ◽  
Cycle Refrigerator

A low cost 12 T pulsed magnet system has been integrated with a closed-cycle helium refrigerator. The copper solenoid is directly immersed in liquid nitrogen for reduced electrical resistance and more efficient heat transfer. This ensures a minimal delay of few minutes between pulses. The sample is mounted on the cold finger of the refrigerator and, along with the surrounding vacuum shroud, is inserted into the bore of the solenoid. When combined with software lock-in signal processing to reduce noise, quick but accurate measurements can be performed at temperatures 4 K-300 K up to 12 T. Quantum Hall effect data in a p -channel SiGe / Si heterostructure has been used to calibrate the instrument against a commercial superconducting magnet. Its versatility as a routine characterization tool is demonstrated by measuring parallel conduction in Si / SiGe modulation doped heterostructures.

Mechanical design of a dual-cryostat instrument for a high-field pulsed magnet

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
D. Capatina ◽  
Z. Islam ◽  
E. Trakhtenberg ◽  
H. Nojiri ◽  
Y. Narumi
Keyword(s):  
Liquid Nitrogen ◽  
High Field ◽  
Mechanical Design ◽  
Closed Cycle ◽  
Pulsed Magnet ◽  
Magnet Coil ◽  
Liquid Nitrogen Cooling ◽  
Photon Source ◽  
Cycle Refrigerator ◽  
Closed Cycle Refrigerator

The engineering of a dual-cryostat for a pulsed-magnet instrument at the Advanced Photon Source is presented. The dual-cryostat independently cools the magnet coil (using liquid-nitrogen) and the sample (using a closed-cycle refrigerator). Liquid-nitrogen cooling may allow a repetition rate of a few minutes for peak fields near 30 T. The system is unique in that the liquid-nitrogen cryostat incorporates a double-funnel vacuum tube passing through the solenoid's bore in order to preserve the entire angular range allowed by the magnet bore for scattering studies. Second, the use of a separate refrigerator for the sample allows precise positioning of samples in the bore while minimizing magnet vibrations propagating to the sample during pulsed-field generation.

scholarly journals 5 MW Closed Cycle Gas Turbine

1984 ◽  
Author(s):  
John L. Mason ◽  
Anthony Pietsch ◽  
Theodore R. Wilson ◽  
Allen D. Harper
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Oil Recovery ◽  
Low Cost ◽  
Pressure Ratio ◽  
Commercial Application ◽  
Solid Fuels ◽  
Closed Cycle ◽  
Emission Standards ◽  
Fluidized Bed Combustor

A novel closed-cycle gas turbine power system is now under development by the GWF Power Systems Company for cogeneration applications. Nominally the system produces 5 megawatts (MW) of electric power and 80,000 lb/hr (36,287 kg/hr) of 1000 psig (6895 kPa) steam. The heat source is an atmospheric fluidized bed combustor (AFBC) capable of using low-cost solid fuels while meeting applicable emission standards. A simple, low-pressure ratio, single spool, turbomachine is utilized. This paper describes the system and related performance, as well as the development and test efforts now being conducted. The initial commercial application of the system will be for Enhanced Oil Recovery (EOR) of the heavy crudes produced in California.

scholarly journals Development of a Cryogen-Free Compact 3 T Superconducting Magnet for an Electromagnetic Property Measurement System

2021 ◽  
Vol 11 (7) ◽  
pp. 3074
Author(s):  
Jae Young Jang ◽  
Myung Su Kim ◽  
Young Jin Hwang ◽  
Seunghyun Song ◽  
Yojong Choi ◽  
...  
Keyword(s):  
High Temperature ◽  
Measurement System ◽  
Electromagnetic Property ◽  
Superconducting Magnet ◽  
Optimized Design ◽  
Magnet System ◽  
Superconducting Tape ◽  
High Temperature Superconducting ◽  
Target Field ◽  
Property Measurement

A cryogen-free portable 3 T high-temperature superconducting magnet for an electromagnetic property measurement system has been developed to serve as a user facility at the Korea Basic Science Institute. The metallic insulation method was adopted to reduce the charging delay without sacrificing the self-protecting feature. A genetic-algorithm-aided optimized design was carried out to minimize the superconducting tape consumption while satisfying several design constraints. After the design, the compact high-temperature superconducting magnet composed of eight double-pancake coil modules was wound with high-temperature superconducting tape and stainless steel tape, and integrated with a two-stage cryo-cooler. The 3 T magnet was successfully cooled to approximately 20 K with a cryo-cooler and reached the target field of 3 T without any problems. Long-term measurements and a range of other tests were also implemented to verity the performance of the magnet. Test results demonstrated the feasibility of a cryogen-free portable high-temperature superconducting magnet system for electromagnetic property measurement experiments.

A Safety Analysis of the ITER Superconducting Magnet System in Case of Loss of Vacuum in the ITER Cryostat

1996 ◽  
Vol 30 (3P2B) ◽  
pp. 1253-1257
Author(s):  
Takashi Kato ◽  
Kunihiro Matsui ◽  
Susumu Shimamoto ◽  
Kazuhiko Nishida ◽  
Tadaaki Honda ◽  
...  
Keyword(s):  
Superconducting Magnet ◽  
Safety Analysis ◽  
Magnet System ◽  
Superconducting Magnet System

Pressure, temperature and helium mass flow development during a quench in the UNK superconducting magnet system

1992 ◽  
Vol 28 (1) ◽  
pp. 186-189 ◽  
Author(s):  
V.I. Deev ◽  
V.S. Kharitonov ◽  
V.V. Shako ◽  
A.I. Ageyev ◽  
S.R. Bakhuliev ◽  
...  
Keyword(s):  
Mass Flow ◽  
Superconducting Magnet ◽  
Magnet System ◽  
Flow Development ◽  
Superconducting Magnet System
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