scholarly journals Design and Development of a Reduced Form-Factor High Accuracy Three-Axis Teslameter

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 368 ◽  
Author(s):  
Johann Cassar ◽  
Andrew Sammut ◽  
Nicholas Sammut ◽  
Marco Calvi ◽  
Sasa Dimitrijevic ◽  
...  
Keyword(s):  
Broadband Noise ◽  
Reduced Form ◽  
Hall Probe ◽  
Digital Conversion ◽  
X Ray ◽  
New Instrument ◽  
Absolute Encoder ◽  
Paul Scherrer ◽  
Analogue To Digital ◽  
Performance Results

A novel three-axis teslameter and other similar machines have been designed and developed for SwissFEL at the Paul Scherrer Institute (PSI). The developed instrument will be used for high fidelity characterisation and optimisation of the undulators for the ATHOS soft X-ray beamline. The teslameter incorporates analogue signal conditioning for the three-axes interface to a SENIS Hall probe, an interface to a Heidenhain linear absolute encoder and an on-board high-resolution 24-bit analogue-to-digital conversion. This is in contrast to the old instrumentation setup used, which only comprises the analogue circuitry with digitization being done externally to the instrument. The new instrument fits in a volumetric space of 150 mm × 50 mm × 45 mm, being very compact in size and also compatible with the in-vacuum undulators. This paper describes the design and the development of the different components of the teslameter. Performance results are presented that demonstrate offset fluctuation and drift (0.1–10 Hz) with a standard deviation of 0.78 µT and a broadband noise (10–500 Hz) of 2.05 µT with an acquisition frequency of 2 kHz.

scholarly journals Performance Analysis of a Reduced Form-Factor High Accuracy Three-Axis Teslameter

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1230 ◽  
Author(s):  
Johann Cassar ◽  
Andrew Sammut ◽  
Nicholas Sammut ◽  
Marco Calvi ◽  
Sasa Spasic ◽  
...  
Keyword(s):  
Analog Signal ◽  
Reduced Form ◽  
Hall Probe ◽  
Signal Conditioning ◽  
Cross Sectional ◽  
New Instrument ◽  
Absolute Encoder ◽  
Paul Scherrer ◽  
Signal Conditioning Circuitry

In the framework of the SwissFEL project at the Paul Scherrer Institute (PSI), a Hall probe bench is being developed for the high-precision magnetic characterization of the insertion devices for the ATHOS soft X-ray beamline. For this purpose, a novel three-axis teslameter has been developed, which will be placed between the undulator and its outer shell in a very limited volumetric space of 150 x 50 x 45 mm. Together with a Hall probe at the center of the cross sectional area of the undulator, the setup will traverse along the undulator length on a specifically designed rig with minimal vibrations. This teslameter has all the analog signal conditioning circuitry for the Hall probe and also has on board 24-bit digitization. The instrument also handles an interface to a linear absolute encoder. The old instrumentation used only had analog signal conditioning circuitry whilst digitization was done off board. The new instrument also provides a very accurate magnetic field map in the µT range with simultaneous readings from the position encoder at an accuracy of ±3 µm. In this paper, a series of tests are described, which were performed at PSI in order to establish the measuring precision and repeatability of the instrument.

scholarly journals Calibration and Characterization of a Reduced Form-Factor High Accuracy Three-Axis Teslameter

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 151
Author(s):  
Johann Cassar ◽  
Andrew Sammut ◽  
Nicholas Sammut ◽  
Marco Calvi ◽  
Zarko Mitrovic ◽  
...  
Keyword(s):  
Form Factor ◽  
Measurement Techniques ◽  
Calibration Procedure ◽  
Reduced Form ◽  
Hall Probe ◽  
X Ray ◽  
Temperature Offset ◽  
Paul Scherrer ◽  
Reference Fields

A new reduced form-factor three axes digital teslameter, based on the spinning current technique, has been developed. This instrument will be used to characterize the SwissFEL insertion devices at the Paul Scherrer Institute (PSI) for the ATHOS soft X-ray beamline. A detailed and standardized calibration procedure is critical to optimize the performance of this precision instrument. This paper presents the measurement techniques used for the corrective improvements implemented through non-linearity, temperature offset, temperature sensitivity compensation of the Hall probe and electronics temperature compensation. A detailed quantitative analysis of the reduction in errors on the application of each step of the calibration is presented. The percentage peak error reduction attained through calibration of the instrument for reference fields in the range of ±2 T is registered to drop from 1.94% down to 0.02%.

scholarly journals Magnetic assessment and modelling of the Aramis undulator beamline

2018 ◽  
Vol 25 (3) ◽  
pp. 686-705 ◽  
Author(s):  
M. Calvi ◽  
C. Camenzuli ◽  
R. Ganter ◽  
N. Sammut ◽  
Th. Schmidt
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurement ◽  
Hall Probe ◽  
Measurement Equipment ◽  
Series Production ◽  
Close Collaboration ◽  
X Ray ◽  
Short Period ◽  
Reduction Methods ◽  
Paul Scherrer

Within the SwissFEL project at the Paul Scherrer Institute (PSI), the hard X-ray line (Aramis) has been equipped with short-period in-vacuum undulators, known as the U15 series. The undulator design has been developed within the institute itself, while the prototyping and the series production have been implemented through a close collaboration with a Swiss industrial partner, Max Daetwyler AG, and several subcontractors. The magnetic measurement system has been built at PSI, together with all the data analysis tools. The Hall probe has been designed for PSI by the Swiss company SENIS. In this paper the general concepts of both the mechanical and the magnetic properties of the U15 series of undulators are presented. A description of the magnetic measurement equipment is given and the results of the magnetic measurement campaign are reported. Lastly, the data reduction methods and the associated models are presented and their actual implementation in the control system is detailed.

scholarly journals An Evaluation of Cellular Neural Networks for the Automatic Identification of Cephalometric Landmarks on Digital Images

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Rosalia Leonardi ◽  
Daniela Giordano ◽  
Francesco Maiorana
Keyword(s):  
Neural Networks ◽  
Cellular Neural Networks ◽  
Automatic Identification ◽  
Cephalometric Analysis ◽  
X Rays ◽  
X Ray ◽  
Automatic Location ◽  
Landmark Identification ◽  
The Mean ◽  
Analogue To Digital

Several efforts have been made to completely automate cephalometric analysis by automatic landmark search. However, accuracy obtained was worse than manual identification in every study. The analogue-to-digital conversion of X-ray has been claimed to be the main problem. Therefore the aim of this investigation was to evaluate the accuracy of the Cellular Neural Networks approach for automatic location of cephalometric landmarks on softcopy of direct digital cephalometric X-rays. Forty-one, direct-digital lateral cephalometric radiographs were obtained by a Siemens Orthophos DS Ceph and were used in this study and 10 landmarks (N, A Point, Ba, Po, Pt, B Point, Pg, PM, UIE, LIE) were the object of automatic landmark identification. The mean errors and standard deviations from the best estimate of cephalometric points were calculated for each landmark. Differences in the mean errors of automatic and manual landmarking were compared with a 1-way analysis of variance. The analyses indicated that the differences were very small, and they were found at most within 0.59 mm. Furthermore, only few of these differences were statistically significant, but differences were so small to be in most instances clinically meaningless. Therefore the use of X-ray files with respect to scanned X-ray improved landmark accuracy of automatic detection. Investigations on softcopy of digital cephalometric X-rays, to search more landmarks in order to enable a complete automatic cephalometric analysis, are strongly encouraged.

Charge density studies of 3dmetal (Ni/Cu) complexes with a non-innocent ligand

2017 ◽  
Vol 73 (4) ◽  
pp. 634-642 ◽  
Author(s):  
Yu-Chun Chuang ◽  
Chou-Fu Sheu ◽  
Gene-Hsiang Lee ◽  
Yu-Sheng Chen ◽  
Yu Wang
Keyword(s):  
High Resolution ◽  
Charge Density ◽  
Reduced Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxidation Reduction ◽  
Square Planar ◽  
Square Planar Complexes ◽  
X Ray Absorption ◽  
Cu Complexes

High-resolution X-ray diffraction experiments and atom-specific X-ray absorption experiments are applied to investigate a series of square planar complexes with the non-innocent ligand of maleonitriledithiolate (mnt), [S2C2(CN)2]z−, containingM—S bonds. Four complexes of (PyH)z[M(mnt)2]z−, whereM= Ni or Cu,z= 2 or 1 and PyH+= C5NH6+, were studied in order to clarify whether such one-electron oxidation–reduction, [M(mnt)2]2−/[M(mnt)2]1−, is taking place at the metal or the ligand site. Combining the techniques of metalK-,L-edge and SK-edge X-ray absorption spectroscopy with high-resolution X-ray charge density studies, it is unambiguously demonstrated that the electron redox reaction is ligand based and metal based for Ni and Cu pairs, respectively. The bonding characters in terms of topological properties associated with the bond critical points are compared between the oxidized form [ML]−and the reduced form [ML]2−. In the case of Ni complexes, the formal oxidation state of Ni remains as Ni2+and each mnt ligand carries a 2− charge in [Ni(mnt)2]2−, but only one of the ligands is formally oxidized in [Ni(mnt)2]1−. In contrast, in the case of Cu complexes, the mnt remains as 2− in both complexes, but the formal oxidation states of the metal are Cu2+and Cu3+. Bond characterizations andd-orbital populations will be presented. The complementary results of XAS, XRD and DFT calculations will be discussed. The conclusion on the redox reactions in these complexes can be firmly established.

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