Angela Intermite | Cockcroft Institute (original) (raw)
Uploads
Papers by Angela Intermite
The QUASAR group combines developments in accelerator sciences with measurements on quantum syste... more The QUASAR group combines developments in accelerator sciences with measurements on quantum system s, with a particular interest in antimatter research. T e group focuses on the development of the key elements of a future ultra-low energy storage ring at the facility for low energy antiproton and ion research. Since its start in 2008 the group substantially br oadened its R&D program, has been collaborating with H IT and CERN on medical accelerators, is pursuing resea ch into superconducting linacs, and is developing beam instrumentation for high energy accelerators.
Silicon Photomultipliers (SiPMs) are semiconductor photo-sensitive devices built from a matrix of... more Silicon Photomultipliers (SiPMs) are semiconductor photo-sensitive devices built from a matrix of Single Photon Avalanche Diodes (SPADs) on a common silicon substrate, working in the limited Geiger mode and with a common readout. The fast counting ability, high timing resolution, immunity to magnetic field up to 15 T, low power consumption and relative small temperature dependence together with the small dimensions make SiPMs excellent candidates as commercially available solid state detectors, and a promising alternative to traditional photomultiplier tubes for single photon detection. Nevertheless, SiPMs do suffer from erroneous counting due to noise effects that can deteriorate their performance. These effects are, in general, heavily dependent on manufacturing quality. In this contribution, results are reported from the characterization of different models of SiPMs in terms of noise spectra and response to light, and a procedure for determining the quality of manufacturing is de...
We present the commissioning results of the MicroChannel-Plate (MCP) based, ion extraction and de... more We present the commissioning results of the MicroChannel-Plate (MCP) based, ion extraction and detection system currently in use for an experimental test stand aimed at demonstrating the operation of a leastinterceptive transverse beam profile monitor based on a planar supersonic gas jet. This monitoring design features least-interceptive operation under excellent vacuum conditions and provides fast acquisition of a bidimensional transverse profile. It bears application for ultra-low energy particle beams at future storage rings, but also for e.g. linacs at high currents and light source injectors. For instance, the Ultra-low energy Storage Ring (USR), part of the Facility for Antiproton and Ion Research (FAIR) in Germany will store antiprotons at energies of 20-300 keV. In this contribution, we report numerical simulations and experimental results obtained by calibration of the detection system with a low energy electron beam to demonstrate a 1 mm imaging resolution only limited by...
The need for real-time monitoring of beam losses, including evaluation of their intensity and loc... more The need for real-time monitoring of beam losses, including evaluation of their intensity and localization of their exact position, together with the possibility to overcome the limitations due to the reduced space for the diagnostics, makes exploitation of the Cherenkov effect in optical fibres, one of the most suitable candidates for beam loss monitoring. In this thesis, the design, development and characterization of an optical fibre beam loss monitor based on high radiation hardness pure silica fibres and silicon photomultipliers is reported. The tests were carried out at the ALICE accelerator research and development facility, Daresbury Laboratories, UK. For this purpose high numerical aperture fibres were used together with the latest generation silicon detector instead of the standard photomultiplier tubes commonly used for Cherenkov beam loss monitoring.
Silicon Photomultipliers (SiPM) are interesting detectors for beam diagnostics applications due t... more Silicon Photomultipliers (SiPM) are interesting detectors for beam diagnostics applications due to their reduced dimensions and costs, and higher photon detection efficiency. Possible applications include longitudinal beam profile measurements by synchrotron light imaging, detection of optical transition radiation for energy spectrum measurements and medical imaging. However, quantitative measurement with SiPMs are jeopardized by the systematic reading error due to Optical Cross-talk (OC), i.e. optical coupling between neighbouring diodes in the array. OC results in overestimation of the impinging light level, and reflects the probability of a triggered avalanche creating a photon of suitable energy and direction to fire a second avalanche in another diode. In this paper, we derive a generalized response distribution for SiPM in presence of OC noise, which overcomes the limitations of assumptions currently made in literature and provides a correction of the SiPM response distributio...
IEEE, 2008
A new fiber strain sensor is presented based on the laser-self-mixing (LSM) effect in distributed... more A new fiber strain sensor is presented based on the laser-self-mixing (LSM) effect in distributed feedback laser diodes (DFB). Compared to existing fiber strain sensors based on fiber Bragg gratings (FBG), our device achieves comparable sensitivity (~1 muepsiv) requiring much simpler electronics. In the moderate feedback regime, sawtooth-like fringes are observed in the optical power emitted by a standard single-mode
Journal of Lightwave …, Jan 1, 2011
Proceedings of …, Jan 1, 2009
The QUASAR group combines developments in accelerator sciences with measurements on quantum syste... more The QUASAR group combines developments in accelerator sciences with measurements on quantum system s, with a particular interest in antimatter research. T e group focuses on the development of the key elements of a future ultra-low energy storage ring at the facility for low energy antiproton and ion research. Since its start in 2008 the group substantially br oadened its R&D program, has been collaborating with H IT and CERN on medical accelerators, is pursuing resea ch into superconducting linacs, and is developing beam instrumentation for high energy accelerators.
Silicon Photomultipliers (SiPMs) are semiconductor photo-sensitive devices built from a matrix of... more Silicon Photomultipliers (SiPMs) are semiconductor photo-sensitive devices built from a matrix of Single Photon Avalanche Diodes (SPADs) on a common silicon substrate, working in the limited Geiger mode and with a common readout. The fast counting ability, high timing resolution, immunity to magnetic field up to 15 T, low power consumption and relative small temperature dependence together with the small dimensions make SiPMs excellent candidates as commercially available solid state detectors, and a promising alternative to traditional photomultiplier tubes for single photon detection. Nevertheless, SiPMs do suffer from erroneous counting due to noise effects that can deteriorate their performance. These effects are, in general, heavily dependent on manufacturing quality. In this contribution, results are reported from the characterization of different models of SiPMs in terms of noise spectra and response to light, and a procedure for determining the quality of manufacturing is de...
We present the commissioning results of the MicroChannel-Plate (MCP) based, ion extraction and de... more We present the commissioning results of the MicroChannel-Plate (MCP) based, ion extraction and detection system currently in use for an experimental test stand aimed at demonstrating the operation of a leastinterceptive transverse beam profile monitor based on a planar supersonic gas jet. This monitoring design features least-interceptive operation under excellent vacuum conditions and provides fast acquisition of a bidimensional transverse profile. It bears application for ultra-low energy particle beams at future storage rings, but also for e.g. linacs at high currents and light source injectors. For instance, the Ultra-low energy Storage Ring (USR), part of the Facility for Antiproton and Ion Research (FAIR) in Germany will store antiprotons at energies of 20-300 keV. In this contribution, we report numerical simulations and experimental results obtained by calibration of the detection system with a low energy electron beam to demonstrate a 1 mm imaging resolution only limited by...
The need for real-time monitoring of beam losses, including evaluation of their intensity and loc... more The need for real-time monitoring of beam losses, including evaluation of their intensity and localization of their exact position, together with the possibility to overcome the limitations due to the reduced space for the diagnostics, makes exploitation of the Cherenkov effect in optical fibres, one of the most suitable candidates for beam loss monitoring. In this thesis, the design, development and characterization of an optical fibre beam loss monitor based on high radiation hardness pure silica fibres and silicon photomultipliers is reported. The tests were carried out at the ALICE accelerator research and development facility, Daresbury Laboratories, UK. For this purpose high numerical aperture fibres were used together with the latest generation silicon detector instead of the standard photomultiplier tubes commonly used for Cherenkov beam loss monitoring.
Silicon Photomultipliers (SiPM) are interesting detectors for beam diagnostics applications due t... more Silicon Photomultipliers (SiPM) are interesting detectors for beam diagnostics applications due to their reduced dimensions and costs, and higher photon detection efficiency. Possible applications include longitudinal beam profile measurements by synchrotron light imaging, detection of optical transition radiation for energy spectrum measurements and medical imaging. However, quantitative measurement with SiPMs are jeopardized by the systematic reading error due to Optical Cross-talk (OC), i.e. optical coupling between neighbouring diodes in the array. OC results in overestimation of the impinging light level, and reflects the probability of a triggered avalanche creating a photon of suitable energy and direction to fire a second avalanche in another diode. In this paper, we derive a generalized response distribution for SiPM in presence of OC noise, which overcomes the limitations of assumptions currently made in literature and provides a correction of the SiPM response distributio...
IEEE, 2008
A new fiber strain sensor is presented based on the laser-self-mixing (LSM) effect in distributed... more A new fiber strain sensor is presented based on the laser-self-mixing (LSM) effect in distributed feedback laser diodes (DFB). Compared to existing fiber strain sensors based on fiber Bragg gratings (FBG), our device achieves comparable sensitivity (~1 muepsiv) requiring much simpler electronics. In the moderate feedback regime, sawtooth-like fringes are observed in the optical power emitted by a standard single-mode
Journal of Lightwave …, Jan 1, 2011
Proceedings of …, Jan 1, 2009