This paper investigates the thermal behavior of axial flux synchronous permanent-magnet machines (AFSPMMs) through a 3-D thermal-magnetic finite-element analysis (FEA). This paper offers a systematic ...approach to magnetothermal FEA. The considered axial flux machine is wound on a soft magnetic compound core. The computation of thermal field is performed via a coupled thermal and fluid-dynamical model based on FEA, where the thermal sources are obtained from a DC current flow model and a magnetostatic model. This paper includes an overview of the finite-element method (FEM) model implementation. Simulation results are presented, and, to validate the model, the simulated surface temperature rise of the motor parts is compared by experimental data.
This paper presents a multiphysics modeling through finite-element (FE) coupled electromagnetic and thermal field analysis of a permanent-magnet tubular linear motor (PMTLM). Two-dimensional ...axial-symmetric FE steady-state and transient solutions are first obtained for the magnetic-flux-density distribution, cogging force, thrust, and losses of the PMTLM prototype. The FE magnetic field results are then used for the 3-D FE thermal simulation to get the PMTLM temperature distribution. This paper proves that the multiphysics numerical field analysis is a viable tool for the design and performance optimization of PMTLMs. The accuracy of the proposed study has been assessed through prior analytical and experimental results. Regarding the design aspects, some peculiarities in the thermal behavior of PMTLMs are emphasized. Generally, thermal models being not ready to develop, experimental and analytical solutions remain a preferred choice.
Laser calibration facilities play a key role in the study and characterization of detectors like electromagnetic or hadronic calorimeters. They can be operated both during physics data taking and off ...runs. Typically, these facilities are based on a laser source which delivers light to each detector element via a light distribution system. The laser control (LC) system typically manages the interface between the experiment and the laser source, allowing the generation of light pulses according to specific needs such as detector calibration, study of detector performance in running conditions, and evaluation of data acquisition performance. Any specific implementation depends on hardware features. As an example, light pulses could be generated according to a physics distribution during physics runs or real data taking. In this case, light pulses should be generated according to a pattern that follows a programmable function and changes on a statistical base event by event. In this paper, we present a LC system for calibration of a calorimeter. It is a custom solution based on a hybrid platform hosting a field-programmable gate array and an ARM processor. We present the system architecture and the performances of a preliminary implementation. This system, in a more specific and specialized version, will be used in the Muon g-2 experiment (E989) at Fermilab.
This paper illustrates the operation of a tubular-machine drive as a linear generator for a heave-buoy wave energy conversion. Linear generators, which are adopted in marine power plants, offer the ...advantage of generating without introducing any conversion crank gear or hydraulic system. The use of a tubular-machine topology allows the electromagnetic thrust density to be improved. This paper briefly summarizes the principles of marine wave buoy interaction and reports the design analysis and control of a permanent-magnet (PM) synchronous tubular linear machine based on a scaled generator prototype and on a rotating simulation test bench
The paper presents a thermal analysis of an axial flux synchronous permanent-magnet machine (AFSPM) with a core of soft magnetic composite (SMC) material. We obtained the temperature distribution by ...using a coupled thermal and fluid dynamic finite-element model. The study considers two 2-D approaches and compares their results to experimental tests.
The Muon g-2 Experiment at Fermilab (E989) will measure the muon magnetic anomaly with unprecedented precision (0.14 ppm), which yields a factor of 4 improvement with respect to the previous ...measurements at Brookhaven National Laboratory (BNL) (E821). To achieve this goal, the relative response of each calorimeter channel must be calibrated and monitored at a level better than <inline-formula> <tex-math notation="LaTeX">10^{-3} </tex-math></inline-formula> in the time window of the muon fill. The calibration system uses a laser source and photodetectors. The data acquisition (DAQ) of the system is designed around two field-programmable gate array (FPGA)-based boards and a custom crate bus. The front-end board manages the photodetector operation and signal processing and performs a first-level data concentration task. Up to 12 FPGA boards can be housed in a 6U crate. A readout master controls the boards, implements event-building functionalities, manages the monitoring interface, and facilitates calibration and debugging tasks. A gigabit-ethernet interface is used to transfer data to the on-line farm for storage and further processing. Presently, the system is working at Fermi National Accelerator Laboratory (FNAL). In this article, we present the DAQ system design, run control user interface, and system evaluation.
A novel numerical approach to calculate the time evolution of the three dimensional distribution of the magnetic field and forces in the end winding regions of large turbine generators is presented. ...The proposed approach is based on an integral formulation for nonlinear magnetostatic problems. Its main advantage is the reduction of the discretization to only the conductors and magnetic materials. In this paper the solution of a coupled magnetostructural problem consisting in the calculation of the mechanical stresses and deformations caused by the electrodynamic forces is presented. The analysis is based on a time stepping simulation where the currents are derived from the integration of a lumped parameter model.
Triggerless DAQ system for a light based detector Mastroianni, S.; Iacovacci, M.; Marignetti, F.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
March 2023, 2023-03-00, Letnik:
1048
Journal Article
Recenzirano
The utilization of various types of photon detectors, generally referred to as light based detectors, is widespread in many fields of high energy physics, nuclear physics, astrophysics and medical ...imaging to measure scintillation photons or Cherenkov light. Both the traditional photomultiplier tubes (PMTs), still the most commonly used, and the silicon photomultipliers (SiPMs) in rapid development in the last years show good performance. The sensitivity down to single photoelectron (PE), the wide dynamic range and the fast timing characteristics can be exploited thanks to a careful optimization of the readout electronics, trigger and DAQ.
In applications where a high efficiency is required at low energy threshold (as for rare-event search experiments), in a typical trigger-based DAQ architecture, lowering the number of coincident signals for the event selection is mandatory with the consequent heavy increase of data rate that could not be sustained by the DAQ chain.
We have developed a triggerless data collection scheme for a light based detector that relies on a new generation of waveform digitizer board, developed by CAEN and able to manage an independent data acquisition on each channel. This paper describes the implementation and the performance of the triggerless DAQ system.
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