Lucio Fiscarelli

Performance of a Fast Digital Integrator in on-field Magnetic Measurements for Particle Accelerators

The fast digital integrator has been conceived to face most demanding magnet test requirements with a resolution of 10 ppm, a signal-to-noise ratio of 105 dB at 20 kHz, a time resolution of 50 ns, an offset of 10 ppm, and on-line processing. In this paper, the on-field achievements of the fast digital integrator are assessed by a specific measurement campaign at the European Organization for Nuclear Research (CERN). At first, the architecture and the metrological specifications of the instrument are reported. Then, the recent on-field achievements of (i) ±10 ppm of uncertainty in the measurement of the main field for superconducting magnets characterization, (ii) ±0.02 % of field uncertainty in quality assessment of small-aperture permanent magnets, and (iii) ±0.15 % of drift, in an excitation current measurement of 600 s under cryogenic conditions, are presented and discussed.

A Model-Driven Domain-Specific Scripting Language for Measurement-System Frameworks

A measurement-domain-specific language, which is based on a model-driven paradigm for measurement-test-procedure definition, instrument configurations, and task synchronization, is proposed. This formal language, which is particular for a specific measurement field, aims at specifying complete, easy-to-understand, easy-to-reuse, and easy-to-maintain applications efficiently and quickly by means of a script. The script is checked and integrated into the existing software framework automatically by a specific parser-builder chain, in order to produce the measurement application. Constructs for abstracting key concepts of the domain allow the test engineer to write more concise and higher level programs by natural language-like sentences in a shorter time without being a skilled programmer. As an experimental case study, the proposed language has been applied to the flexible framework for magnetic measurements at the European Organization for Nuclear Research (CERN).

A software framework for developing measurement applications under variable requirements

A framework for easily developing software for measurement and test applications under highly and fast-varying requirements is proposed. The framework allows the software quality, in terms of flexibility, usability, and maintainability, to be maximized. Furthermore, the development effort is reduced and finalized, by relieving the test engineer of development details. The framework can be configured for satisfying a large set of measurement applications in a generic field for an industrial test division, a test laboratory, or a research center. As an experimental case study, the design, the implementation, and the assessment inside the application to a measurement scenario of magnet testing at the European Organization for Nuclear Research is reported.

Measurement-Domain Specific Language for magnetic test specifications at CERN

A Measurement-Domain Specific Language (MDSL) for test procedure definition, measurement tasks synchronization, and instrument configuration is proposed. MDSL is a formal language specially designed for a specific domain of measurement and test, aimed at specifying complete, easy-to-understand, -reuse, and -maintain applications efficiently and quickly. Owing to MDSL constructs capability of abstracting key concepts of the domain, the test engineer can write more concise and higher level programs in shorter time without being a skilled programmer. The MDSL has been applied to the specifications of superconducting magnet tests of the Large Hadron Collider at CERN.

A Petri Net-Based Software Synchronizer for Automatic Measurement Systems

A Petri net (PN)-based approach to software synchronization in automatic measurement systems is proposed. Tasks are synchronized by means of a PN modeling an execution graph, where nodes represent tasks and arrows among nodes point out time succession among the corresponding tasks. This allows software synchronization to be abstracted above the code level by leaving the test engineer to work at a more intuitive level. As an experimental case study, the design, the implementation, and the application to a measurement scenario of the PN-based synchronizer inside the software framework for testing magnets at the European Organization for Nuclear Research (CERN) are illustrated.

High-performance permeability measurements: A case study at CERN

An accurate and flexible system for magnetic permeability measurements is described. In particular, effects such as eddy currents and signal drift are minimized by exploiting the main system features: (i) high-performance digital integration by means of a digital integrator, with a theoretical resolution of 10 ppt using an 18-Bit A/D Converter at 800 kS/s, specifically developed for magnetic measurements, and (ii) flexibility of the measurement procedure for overcoming magnetic field non-uniformity errors through a procedure specifically generated by means of a flexible software framework. In particular, the theoretical background underlying the measurement, the procedure, and the system architecture are illustrated, as well as experimental results from testing a non-oriented steel are described.

Compensation of third-harmonic field error in LHC main dipole magnets

One of the main requirements for the operations of the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) is a suitable correction of multipole errors in magnetic field. The feed-forward control of the LHC is based on the Field Description for the LHC (FiDel), capable of forecasting the magnets behavior in order to generate adequate current ramps for main and corrector magnets. Magnetic measurements campaigns aimed at validating the model underlying FiDel highlighted the need for improving the harmonic compensation of the third-harmonic (b3) component of the main LHC dipoles. In this paper, the results of a new measurement campaign for b3 harmonic compensation, carried out through the new Fast Acquisition Measurement Equipment (FAME), are reported. In particular, the mechanism and the measurement procedure of the compensation, as well as the new perspectives opened by preliminary experimental results, are illustrated.