141 research outputs found
Reflections on the coming era of artificial intelligence
The quest of every species in the attempt to overcome its bounds and limits to preserve itself for eternity has existed from the very beginning. If one were to analyse all the activity of any sort of life, one may suggest that these efforts point to one primary scope: 'To get an egg from an egg'.peer-reviewe
Performance analysis of a reduced form-factor high accuracy three-axis teslameter
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 × 50 × 45 mm. Together with a SENIS® 3-axis 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.peer-reviewe
Design and development of a reduced form-factor high accuracy three-axis teslameter
Acknowledgments: The authors would like to thank Reuben Debono for his useful guidance and help in the
PCB assembly of the instruments at the Electronic Systems Lab at the Faculty of Engineering at University of
Malta. The authors would like to thank R. Ganter, project leader of the Athos undulator beamline and H-H.
Braun, SwissFEL machine director, for their constant support throughout the entire project. The authors would
like to thank Sasa Spasic and his team at Sentronis facilities for their fruitful discussions and their guidance
during testing.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.peer-reviewe
Calibration and characterization of a reduced form-factor high accuracy three-axis teslameter
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%.peer-reviewe
The status of sustainable social innovation in Malta
Governments are increasingly using social innovation to stimulate economic growth and address social issues sustainably. Unfortunately, due to its size, Malta faces a very different challenge to sustainably kick-start high-value-added innovative ecosystems compared to larger states. This is due to a number of issues, including diseconomies of scale, that tend to impede conventional innovation policy efforts. Based on grassroots data, this paper presents the results of a study which determined the status of social innovation in Malta and presents a few recommended measures that can be implemented in order to stimulate social innovation sustainably in Malta and possibly in similar small jurisdictions.peer-reviewe
Operational results with fast automatic beam-based LHC collimator alignment
The CERN Large Hadron Collider (LHC) is the largest and highest-energy particle accelerator ever built. It is designed to collide particles at a centre-of-mass energy of 14 TeV to explore the fundamental forces and constituents of matter. Due to the potentially destructive high-energy particle beams, with a total design energy of 362 MJ, the collider is equipped with a series of machine protection systems. The beam cleaning or collimation system is designed to passively intercept and absorb particles at large amplitudes. The cleaning efficiency depends heavily on the accurate positioning of the jaws with respect to the beam trajectory. Beam-based collimator alignment is currently the only feasible technique that can be used to determine the beam centre and beam size at the collimator locations. If the alignment is performed without any automation, it can require up to 30 hours to complete for all collimators. This reduces the beam time available for physics experiments. This article provides a brief recap of the algorithms and software developed to automate and speed up the alignment procedure, and presents the operational results achieved with fast automatic beam-based alignment in the 2011-2013 LHC runs.peer-reviewe
Dynamic Ferromagnetic Hysteresis Modelling Using a Preisach-Recurrent Neural Network Model
In this work, a Preisach-recurrent neural network model is proposed to predict the dynamic hysteresis in ARMCO pure iron, an important soft magnetic material in particle accelerator magnets. A recurrent neural network coupled with Preisach play operators is proposed, along with a novel validation method for the identification of the model's parameters. The proposed model is found to predict the magnetic flux density of ARMCO pure iron with a Normalised Root Mean Square Error (NRMSE) better than 0.7%, when trained with just six different hysteresis loops. The model is evaluated using ramp-rates not used in the training procedure, which shows the ability of the model to predict data which has not been measured. The results demonstrate that the Preisach model based on a recurrent neural network can accurately describe ferromagnetic dynamic hysteresis when trained with a limited amount of data, showing the model's potential in the field of materials science
Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets : III. Precycle ramp rate effects and magnet characterization
The Large Hadron Collider (LHC) at CERN is equipped with a feed-forward control system known as the field description for the LHC (FiDeL) which is designed to predict the magnetic field and its multipoles, hence reducing the burden on beam based feedback. FiDeL consists of a physical and empirical parametric field model based on magnetic measurements at warm and in cryogenic conditions. It is particularly critical during beam injection when the field decays and at the beginning of acceleration when the field snaps back. It is known that the decay amplitude is largely affected by the powering history of the magnet, particularly by the precycle flattop current and duration and the preinjection preparation duration. Recently, we have collected data that quantify the dependence of the decay amplitude on the precycle ramp rate. This paper presents the results of the measurements performed to investigate this effect, and the method included in FiDeL to model the precycle dependence.With this complete picture of dynamic changes, we finally discuss the effect on the data taken at nominally constant field, along the magnet loadline. We show that a correction for dynamic changes is required for adequate magnet characterization.peer-reviewe
A novel holistic design optimisation algorithm for the ironless inductive position sensor
The Ironless Inductive Position Sensor (I2PS) is a state-of-the-art high precision linear position sensor, which is designed to be radiation hard and immune to magnetic fields. This sensor is built for the Large Hadron Collider collimation system at the European Organization for Nuclear Research. It is continuously monitored to assess the precision, accuracy and drifts during the machine’s operation. The ironless inductive position sensor was previously designed and optimised manually on a programmed electromagnetic model and simulated using a finite element model simulator. This sensor has the potential to be used extensively in industry, especially in areas with high radiation and high electro-magnetic interference. To industrialise it, an automated design procedure is required that offers the possibility to a user with minimal knowledge to design and optimise the sensor. This paper identifies the optimisation parameters and constants required in the manual design. It hence presents an automated design procedure which uses a multi-objective optimisation algorithm to automatically produce ironless inductive position sensors tailor-made to the user’s specifications.peer-reviewe
National strategy for health research and innovation
In 2011, the Malta Council for Science and Technology (MCST) commissioned the Development of a dedicated strategy for health research and innovation in line
with its mandate from Government to identify areas of national priority and design and to also implement strategic approaches to enhance economic competitiveness
and quality of life. The Strategy was drawn up by a steering group which also included people from outside the health sector, to ensure that it also keeps note of the economic side of things.peer-reviewe
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