A Flexible Search Coil Set-Up for Magnetic Measurements of Accelerator Dipole Magnets

2020 ◽  
Vol 30 (4) ◽  
pp. 1-4
Author(s):  
Carsten Muehle ◽  
Franz Klos ◽  
Thomas Knapp ◽  
Mischa Weipert
Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate.” The performances and limitations of the system are discussed.


Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate." The performances and limitations of the system are discussed.


1982 ◽  
Vol 19 (1) ◽  
pp. 45-52 ◽  
Author(s):  
S. C. Bhargava

The basic principle of search coils is explained by reference to the integral form of Maxwell's equation. The salient features of instrumentation, necessary for search coil applications, are discussed, followed by a brief description of a few typical examples of magnetic measurements by a variety of search coils.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 517-525
Author(s):  
Mohamad El Youssef ◽  
Adrien Van Gorp ◽  
Stéphane Clenet ◽  
Abdelkader Benabou ◽  
Pierre Faverolle ◽  
...  

AbstractIn this article, an experimental procedure is presented to handle magnetic measurements under uniaxial tensile stress reaching the plastic domain. The main advantage of the proposed procedure is that it does not require an additional magnetic core to close the magnetic flux path through the studied sample. The flux flows only in the sample, and no parasitic air gaps are introduced, thus avoiding the use of the H-coil to evaluate the magnetic field, which is often very sensitive and not easy to calibrate. A specimen of nonoriented FeSi (1.3%) sheet (M330-35A) is characterized under uniaxial tensile stress. To validate the proposed procedure, a comparison with the single sheet tester procedure is carried out. The results obtained by the two procedures are in good agreement. Moreover, to illustrate the possibilities offered by the proposed procedure, we confirm some results obtained in the literature. We show that the positive plastic strain leads to a significant degradation of magnetic behavior. An applied tensile stress on a virgin (unstrained) sample leads to a degradation of the magnetic behavior. However, on a pre-strained sample, an applied tensile stress results in reducing the deterioration caused by the plastic strain until a stress value called optimum is attained. Above this threshold, the magnetic behavior re-deteriorates progressively.


2021 ◽  
Vol 69 (1) ◽  
pp. 59-65
Author(s):  
Ionel CHIRIȚĂ ◽  
Nicolae TĂNASE ◽  
Cristinel ILIE ◽  
Marius POPA

This paper presents the constructive design of the Sextupole, Horizontal Steerer and Vertical Steerer electromagnets manufactured by ICPE-CA for HESR storage ring from FAIR Project which will be set-up in Darmstadt Germany. Also, in this paper is presented the current method and system with Hall probe the one that we have performed the magnetic measurements so far by now. Regarding that this method takes a lot of time to perform the magnetic measurements, meanwhile we have developed a system with harmonic coils, which we intend to use in the further magnetic measurements. Also, in this paper is presented the method of magnetic measurements with harmonic coil also the development of mathematical model for this measurement method. To validate the mathematical model of magnetic measurements using harmonic coils we have made a simulation and we have compared with the measurements performed with Hall probe on the Sextupole electromagnet.


Author(s):  
T. G. Naymik

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.


Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.


Author(s):  
O.L. Krivanek ◽  
J. TaftØ

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.


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