M. Ardid - Academia.edu (original) (raw)

Papers by M. Ardid

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009

It is not easy to design a calibrator system able to reproduce the time and directivity patterns ... more It is not easy to design a calibrator system able to reproduce the time and directivity patterns of the acoustic pulse produced in an ultra high energy neutrino interaction. Linear arrays of acoustic transducers with coherent emission have been proposed, but it might result in a long array with many elements, increasing the cost and making the deployment and operation much more complex. In this paper, we evaluate the possibility of using an alternative approach using parametric acoustic sources to generate neutrino-like signals. This non-linear acoustic effect can also be applied to transient signals allowing to generate them by a ''special modulation'' at a larger frequency. The technique has the advantage of being much more directive since the directivity of the parametric source is similar to that of the large frequency used, and therefore it will result in a much more compact design with fewer sources. Here, we present the studies performed with planar transducers in a tank to evaluate the possibilities of the technique, which seems very promising according to our results.

The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been de... more The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deep waters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same 40 K decay and the localisation bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions.

Spectrochimica Acta Part B: Atomic Spectroscopy, 2004

In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispe... more In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispersive X-ray Fluorescence (EDXRF) spectrometers are described. Both the equipments and the techniques employed in the field of the art and archeometry are compared. Some applications in this area are presented as well. The aim of the work is to know which spectrometer is the best suited depending on the work of art and the problem treated. The conclusion reached from the experience is that the portable EDXRF spectrometer is advisable to make bin situQ and online analysis in a multidisciplinary environment, the static EDXRF equipment is good to perform analysis on paper and metal pieces and the TXRF spectrometry is the best technique for very sensitive analysis of trace elements from micro-samples. Within the last technique, we propose to analyze the cottons used by the restorers in the different steps of the restoration process since it could be a good tool to study the composition of different layers and zones of the work of art. D

Sensors, 2012

In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes... more In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters.

Physics Letters B, 2011

A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES ... more A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A (0.83 × 2π) sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an E −2 flux spectrum, a 90% c.l. upper limit on the diffuse ν µ flux of E 2 Φ 90% = 5.3 × 10 −8 GeV cm −2 s −1 sr −1 in the energy range 20 TeV -2.5 PeV is obtained. Other signal models with different energy spectra are also tested and some rejected.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004

The prints are fragile and delicate art objects that need for its examination a suitable techniqu... more The prints are fragile and delicate art objects that need for its examination a suitable technique for ''in situ'', nondestructive and rapid analyses. The energy dispersive X-ray Fluorescence (EDXRF) spectrometry with portable instrumentation offers these analytical properties. In this work we present the EDXRF analyses of eight engravings elaborated with different techniques (etching and heliogravure) from the 17th to 20th centuries. The characterization of the paper is directly done from its EDXRF spectra, whereas the inks are characterized by the ink plus paper analysis after subtracting the background from the paper spectrum. Inorganic components of the paper engravings and inks have been identified from the EDXRF spectra and the results are discussed. Also, we present EDXRF analyses for the identification of inorganic components from six samples of modern inks.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002

We describe the design of the secondary pion beam-line installed at the SIS 18Tm synchrotron at G... more We describe the design of the secondary pion beam-line installed at the SIS 18Tm synchrotron at GSI, Darmstadt, and discuss the commissioning results. The experiments were performed with proton and 12 C primary beams at several energies using beryllium production targets. Pion yields in a momentum range between 0.4 and 2:8 GeV=c were identified. At the highest primary beam energies of 3:5 GeV for proton and 2:0 A GeV for carbon ions, the latter beam produces the highest low-momentum pion yield while at momenta of 1:5 GeV=c the yields are comparable and at 2:8 GeV=c the proton beam is superior. A momentum resolution of around 0.5% is achieved and the time resolution (s) ranges from 100 to 150 ps, for bombarding rates up to 1:5 MHz. r (J. D! ı ıaz).

The European Physical Journal C, 2013

We analyse the application in aquaculture of acoustical techniques to monitor the biomass in open... more We analyse the application in aquaculture of acoustical techniques to monitor the biomass in open sea Mediterranean cages. We describe the problems when applying sonar techniques to the determination of density, behaviour or growth rate of gilthead sea bream in open sea cages in the Mediterranean. We propose different strategies and research lines from first principles, addressed to obtain a simple setup based on no expensive single beam transducers, capable to be installed in production conditions.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009

It is not easy to design a calibrator system able to reproduce the time and directivity patterns ... more It is not easy to design a calibrator system able to reproduce the time and directivity patterns of the acoustic pulse produced in an ultra high energy neutrino interaction. Linear arrays of acoustic transducers with coherent emission have been proposed, but it might result in a long array with many elements, increasing the cost and making the deployment and operation much more complex. In this paper, we evaluate the possibility of using an alternative approach using parametric acoustic sources to generate neutrino-like signals. This non-linear acoustic effect can also be applied to transient signals allowing to generate them by a ''special modulation'' at a larger frequency. The technique has the advantage of being much more directive since the directivity of the parametric source is similar to that of the large frequency used, and therefore it will result in a much more compact design with fewer sources. Here, we present the studies performed with planar transducers in a tank to evaluate the possibilities of the technique, which seems very promising according to our results.

The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been de... more The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deep waters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same 40 K decay and the localisation bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions.

Spectrochimica Acta Part B: Atomic Spectroscopy, 2004

In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispe... more In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispersive X-ray Fluorescence (EDXRF) spectrometers are described. Both the equipments and the techniques employed in the field of the art and archeometry are compared. Some applications in this area are presented as well. The aim of the work is to know which spectrometer is the best suited depending on the work of art and the problem treated. The conclusion reached from the experience is that the portable EDXRF spectrometer is advisable to make bin situQ and online analysis in a multidisciplinary environment, the static EDXRF equipment is good to perform analysis on paper and metal pieces and the TXRF spectrometry is the best technique for very sensitive analysis of trace elements from micro-samples. Within the last technique, we propose to analyze the cottons used by the restorers in the different steps of the restoration process since it could be a good tool to study the composition of different layers and zones of the work of art. D

Sensors, 2012

In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes... more In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters.

Physics Letters B, 2011

A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES ... more A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A (0.83 × 2π) sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an E −2 flux spectrum, a 90% c.l. upper limit on the diffuse ν µ flux of E 2 Φ 90% = 5.3 × 10 −8 GeV cm −2 s −1 sr −1 in the energy range 20 TeV -2.5 PeV is obtained. Other signal models with different energy spectra are also tested and some rejected.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004

The prints are fragile and delicate art objects that need for its examination a suitable techniqu... more The prints are fragile and delicate art objects that need for its examination a suitable technique for ''in situ'', nondestructive and rapid analyses. The energy dispersive X-ray Fluorescence (EDXRF) spectrometry with portable instrumentation offers these analytical properties. In this work we present the EDXRF analyses of eight engravings elaborated with different techniques (etching and heliogravure) from the 17th to 20th centuries. The characterization of the paper is directly done from its EDXRF spectra, whereas the inks are characterized by the ink plus paper analysis after subtracting the background from the paper spectrum. Inorganic components of the paper engravings and inks have been identified from the EDXRF spectra and the results are discussed. Also, we present EDXRF analyses for the identification of inorganic components from six samples of modern inks.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002

We describe the design of the secondary pion beam-line installed at the SIS 18Tm synchrotron at G... more We describe the design of the secondary pion beam-line installed at the SIS 18Tm synchrotron at GSI, Darmstadt, and discuss the commissioning results. The experiments were performed with proton and 12 C primary beams at several energies using beryllium production targets. Pion yields in a momentum range between 0.4 and 2:8 GeV=c were identified. At the highest primary beam energies of 3:5 GeV for proton and 2:0 A GeV for carbon ions, the latter beam produces the highest low-momentum pion yield while at momenta of 1:5 GeV=c the yields are comparable and at 2:8 GeV=c the proton beam is superior. A momentum resolution of around 0.5% is achieved and the time resolution (s) ranges from 100 to 150 ps, for bombarding rates up to 1:5 MHz. r (J. D! ı ıaz).

The European Physical Journal C, 2013

We analyse the application in aquaculture of acoustical techniques to monitor the biomass in open... more We analyse the application in aquaculture of acoustical techniques to monitor the biomass in open sea Mediterranean cages. We describe the problems when applying sonar techniques to the determination of density, behaviour or growth rate of gilthead sea bream in open sea cages in the Mediterranean. We propose different strategies and research lines from first principles, addressed to obtain a simple setup based on no expensive single beam transducers, capable to be installed in production conditions.