Measurement of AC Profiles of Magnetic Field Above HTSc Tape Using Hall Probe Technique With Help of DAQ Cards and Triggering

2005 ◽  
Vol 15 (2) ◽  
pp. 3660-3663 ◽  
Author(s):  
L. Frolek ◽  
E. Demencik
1992 ◽  
Vol 63 (4) ◽  
pp. 2259-2262 ◽  
Author(s):  
Jue Zhang ◽  
P. Sheldon ◽  
R. K. Ahrenkiel

2012 ◽  
Vol 1434 ◽  
Author(s):  
Kohei Higashikawa ◽  
Kei Shiohara ◽  
Masayoshi Inoue ◽  
Takanobu Kiss ◽  
Masateru Yoshizumi ◽  
...  

ABSTRACTTo enhance a global critical current in a superconductor, it is indispensable to understand current limiting factors and their influence on such a critical current. From this point of view, we have investigated in-plane distribution of local critical current density and its electric field criterion in a thin-film superconductor by using scanning-Hall probe microscopy. In a remanent state, after the application of sufficiently high magnetic field to a sample, current flows at critical current density according to the critical state model. Such distribution of current density was estimated from that of measured magnetic field using the Biot-Savart law. Furthermore, the corresponding electric field criterion was evaluated from the relaxation of such remanent magnetic field by considering Faraday’s law. This means that we could estimate in-plane distribution of local critical current density as a function of electric field criterion in a nondestructive manner. This characterization method would be very helpful for finding current limiting factors in a thin-film superconductor and their influence on its global current density versus electric field properties which would usually be obtained by four-probe method.


Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 541 ◽  
Author(s):  
Pengyu Wang ◽  
Jinxing Zheng ◽  
Yuntao Song ◽  
Wuquan Zhang ◽  
Ming Wang

The purpose of this study is to provide an energy verification method for the nozzle of the SC200 proton therapy facility to ensure safe redundancy of treatment. This paper first introduces the composition of the energy selection system of the SC200 proton therapy facility. Secondly, according to IEC60601 standard, the energy verification requirement that correspond to 1 mm error in water is presented. The allowable difference between the measured magnetic field and the reference are calculated based on the energy verification requirements to select the field resolution of the Hall probe. To ensure accuracy and stability, two Hall probes are mounted on the dipole to monitor the magnetic field strength to verify the proton beam energy in real time. In addition, the test results of the residual field of the dipole show that the probe system meets the accuracy requirements of energy verification. Furthermore, the maximum width of the slit of the energy selection system in accordance with the IEC standard at the corresponding energy is calculated and compared with the actual position of the movable slit to verify the momentum divergence of the proton beam. Finally, we present an energy verification method.


1999 ◽  
Vol 70 (6) ◽  
pp. 2703-2707 ◽  
Author(s):  
C. Schott ◽  
R. S. Popovic ◽  
S. Alberti ◽  
M. Q. Tran

2012 ◽  
Vol 457-458 ◽  
pp. 884-890
Author(s):  
Megumi Uryu ◽  
Katsuyuki Kida ◽  
Takashi Honda ◽  
Kenichi Saruwatari ◽  
Edson Costa Santos ◽  
...  

Fatigue failure of machine components occurs when cracks form in the stress concentration area and propagate under continued loading during component work. In order to understand the relation between the phenomena of stress concentration and crack propagation, non-destructive evaluation methods using in-situ measurements in the stress concentration areas are necessary. In the present work, a scanning Hall probe microscope (SHPM) equipped with a GaAs film sensor was developed and the three dimensional magnetic fields were observed at room temperature in air. The effect of stress on the changes in the magnetic field in steel components is reported. A steel specimen (JIS SKS93) embedded in acrylic resin were strained at different loads and the magnetic field before and after straining were observed. The obtained magnetic images clearly corresponded with the shape of the steel plate. It was possible to measure the changes in the magnetic field of the steel sample after straining under tensile loading, by neutralizing the initial magnetic field of the specimens prior to testing.


1979 ◽  
Vol 50 (4) ◽  
pp. 2945-2947 ◽  
Author(s):  
H. T. Minden ◽  
M. F. Leonard

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