Разработка и исследование измерительного комплекса для определения гиромагнитного отношения протона в воде методом "слабого поля"

• Автор: Парк По Гю
• Шифр специальности: 05.11.01
• Научная степень: Кандидатская
• Год защиты: 2001
• Место защиты: Санкт-Петербург
• Количество страниц: 112 с.

Contents
Introduction
Chapter 1. Review and determination of research subject
§1.1. Review of a y'P - measurements
§ 1.2. Grounding of common structure of the measuring system
Chapter 2. Measuring system and technique for determination
of the solenoid constant via winding dimensions
§2.1. Multi-current precision uniform field solenoid with
constant independent from averaged diameter
§ 2.2. Measuring system for determination of a solenoid
dimensions
§ 2.3. Absolute determination of a constant of a solenoid
Chapter 3. Apparatus and experiment on measurement of the gyromagnetic ratio of 4He atoms in terms of that of the 3He nuclei
§ 3.1. Applied magnetic resonance technique with the
polarization by a optical pumping method
§ 3.2. Measurement of the gyromagnetic ratio of 4He
atoms in terms of that of the 3He nuclei
Chapter 4. Measuring system for determination of the 4He
atoms gyromagnetic ratio
§4.1. Nonmagnetic environment
§ 4.2. General structure of the measuring system
§ 4.3. Atom-resonance based current source

§ 4.4. The system for automatic compensation of the
Earth magnetic field
§ 4.5. Results of the 4He atoms and proton gyromagnetic
ratio determination
Conclusion
References
Introduction

Topicality of work
The proton gyromagnetic ratio in water - y'P represents the physical interconnection of the magnetic field and the Zeeman magnetic resonance frequency in the system of fundamental physical constants.
The y'P is one of the basic constants for establishing of the main standards of the electromagnetic SI units, for example, the quantum Hall resistance:

and for testing of the fundamental physical theory via the determination of the fine-structure constant(a) in particular, according to the following relation:

2RoRJ[Y'p]lab

where p0 is a magnetic susceptibility of vacuum, c is the speed of light in vacuum, p /pB is a magnetic moment of a proton in terms of Bohr magneton, Rx is a Ridberg constant, RH is a the quantum Hall constant, 2e/h is a Josephson constant; the index LAB means, that the constants are measured in comparable laboratory units.
Therefore knowledge reliability increase of this world constant, to which the researches of the given work were directed, without any doubts remains an actual problem of the fundamental metrology.
Along with a value of y'P for the fundamental metrology, this constant plays a crucial role in achieving of a high accuracy magnetic measurements.

The results of the comparative analysis of the calculated attainable homogeneity of magnetic field executed by two described above methods, for cases of application 1,2,3,4, and 5 current supply systems of winding, are shown on Fig.2.9. It is evident from Fig.2.9, that the five-current system just achieves required field uniformity (1 x 10"7) inside the required working space (±2 cm) beside more simple current configurations.
§ 2.2. Measuring system for determination of a solenoid dimensions
The 10-turns positions and radius variations were measured with the noncontacting induction method proposed in [35],[53], but with an important modification in this work improving the measurements result. It relates to AC injection system and to DC return lead.
A line of 103 small contact pivots with 102 double-wire twisted 30 cm cables has been installed on the solenoid to energize each 10-tum group for non-contact dimension measurements. Each cable connects one pivot pair to a small connector. At the AC experiment all pivots were connected to the solenoid, so that we could inject AC into any group. At the DC experiment all pivots (except those used for DC) were disconnected from the solenoid, open connectors were closed and the series conductor line with closed cables served as a solenoid return lead. Such a device enables to avoid two problems (with their errors): the tracing system for the moving fork-shaped AC injector and geometry imperfections of the DC return lead. The imperfections of the series conductor line prove automatically compensated as the same leads participate in the both experiments [74]. It is the main advantage of modification, proposed in this work.
The laser beam passed through vacuum in the solenoid with low air pressure (13 to 26) Pa. The sine-wave currents of 0.72 A at 146.5 Hz, 323.5 Hz, and 519.5 Hz were used.