1991 Fiscal Year Final Research Report Summary
Very High Precision Measurements of Quqntized Hall Resistances
| Project/Area Number |
03044126
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Gakushuin University |
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Principal Investigator |
KAWAJI Shinji Gakushuin University, Faculty of Science・Professor, 理学部, 教授 (00080440)
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| Co-Investigator(Kenkyū-buntansha) |
RICKETTS B. W. Csiro・Nml・Senior Scientist, CSIRO National Measurement Labor, 主任研究員
SMALL G. W. Csiro・Nml・Principal Scientist, CSIRO National Measurement Labor, 主幹研究員
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| Project Period (FY) |
1991
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| Keywords | quantized Hall resistance / quantum Hall effect / high precision measurement |
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| Research Abstract |
On behalf of the Head Investigator, Nagata, M. (graduate student of Gakushuin University) visited CSIRO ・ NML with@a 1 OMEGA standard resistor. He stayed there for 23 days and investigated works carried out by the Impedance Group ; (1) the manufacture of 1 OMEGA standard resistors and the calibration of them based on a calculable capacitor, (2) comparisons between 1 OMEGA standard resistors, (3) (6453+9/4) OMEGA Build-Up Resistor, @ (4) @Cryogenic Current Comparator planning. A new 1 OMEGA standard resistor was carried by his own hands to Gakushuin University. Dr. Sniall visited Gakushuin University to collaborate with Kawaji's group for 2 weeks in improving the Cryogenic Current Comparator System for the very high precision measurements of quantized Hall resistances. Dr. Small enabled to use the Cryogenic Current Comparator System for the QHR (quantized Hall resistance) measurements except a 0.02 ppm level error. Dr. Ricketts visited Gakushiuin University with a calibrated 10 kOMEGAresistor to remove the 0.02 ppm level error in the Cryogenic Current Comparator System. He stayed for 13 days. After finding the origin of the error, measurements of QHR with the quantum number 2 and 4 measurements were carried out. The average value of four measurements of QHR with the quantum number 2, R_H (2), is described as [2xR_H(2)/25812.8 OMEGA _<SI-SCIRO>]-1=[0.385 (+0.03) <minus-plus>0.01] ==, wjere (+0.03) ppm uncertainty is a possible statematic uncertainty which is under investigation a person. The average value of two QHR measurements with the quantum number 4, Ru (4), is 0.01 ppm larger than R_H (2) although they are in agreement within their uncertainties.
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