A high-precision position measurement instrument for collimators

An innovative high-precision digital instrument for position measurement of particle accelerators collimators is proposed. The instrument relies on Linear Variable Differential Transformer by exploiting the three-parameter sine fit to estimate the amplitudes of their secondary signals. Moreover, the crucial problem of interfering magnetic fields is thoroughly analyzed by means of two different models: an analytical one aimed at capturing the main physics of the phenomenon and a predictive one based on Finite Elements Method. Both models have been validated by means of simulations and experimental measurements. They provide a basis for design guidelines to an application-independent solution of the interference problem. The experimental validation of the models comprises the development of a measurement method and a measurement system for the general characterization of external magnetic fields as influence quantities for the position measurement by means of Linear Variable Differential Transformer sensors. Preliminary on-field results, gathered during Large Hadron Collider commissioning and operation at CERN, confirming the laboratory results are reported.

Autorentext

Michele Martino received both MD in Electronics Engineering (magna cum laude) and PhD in Electrical Engineering at University of Napoli Federico II. Control system designer at FIAT, 2004. Fellow at INFN, 2005: LHCb muon front end electronics test. At CERN since 2006, currently project engineer - High Precision Measurement - Power Converters Group.