A large area 100 channel Picosec Micromegas detector with sub 20 ps time resolution

The PICOSEC Micromegas precise timing detector is based on a Cherenkov radiator coupled to a semi-transparent photocathode and a Micromegas amplification structure. The first proof of concept single-channel small area prototype was able to achieve time resolution below 25 ps. One of the crucial aspects in the development of the precise timing gaseous detectors applicable in high-energy physics experiments is a modular design that enables large area coverage. The first 19-channel multi-pad prototype with an active area of approximately 10 cm$^2$ suffered from degraded timing resolution due to the non-uniformity of the preamplification gap. A new 100 cm$^2$ detector module with 100 channels based on a rigid hybrid ceramic/FR4 Micromegas board for improved drift gap uniformity was developed. Initial measurements with 80 GeV/c muons showed improvements in timing response over measured pads and a time resolution below 25 ps. More recent measurements with a new thinner drift gap detector module and newly developed RF pulse amplifiers show that the resolution can be enhanced to a level of 17~ps. This work will present the development of the detector from structural simulations, design, and beam test commissioning with a focus on the timing performance of a thinner drift gap detector module in combination with new electronics using an automated timing scan method

Towards robust PICOSEC Micromegas precise timing detectors

The PICOSEC Micromegas (MM) detector is a precise timing gaseous detector consisting of a Cherenkov radiator combined with a photocathode and a MM amplifying structure. A 100-channel non-resistive PICOSEC MM prototype with 10x10 cm^2 active area equipped with a Cesium Iodide (CsI) photocathode demonstrated a time resolution below 18 ps. The objective of this work is to improve the PICOSEC MM detector robustness aspects; i.e. integration of resistive MM and carbon-based photocathodes; while maintaining good time resolution. The PICOSEC MM prototypes have been tested in laboratory conditions and successfully characterised with 150 GeV/c muon beams at the CERN SPS H4 beam line. The excellent timing performance below 20 ps for an individual pad obtained with the 10x10 cm^2 area resistive PICOSEC MM of 20 MOhm/sq showed no significant time resolution degradation as a result of adding a resistive layer. A single-pad prototype equipped with a 12 nm thick Boron Carbide (B4C) photocathode presented a time resolution below 35 ps; opening up new possibilities for detectors with robust photocathodes. The results made the concept more suitable for the experiments in need of robust detectors with good time resolution

Studying common ground instantiation using audio, video and brain behaviours: the BrainKT corpus

International audienceAn increasing amount of multimodal recordings has been paving the way for the development of a more automatic way to study language and conversational interactions. However this data largely comprises of audio and video recordings, leaving aside other modalities that might complement this external view of the conversation but might be more difficult to collect in naturalistic setups, such as participants brain activity. In this context, we present BrainKT, a natural conversational corpus with audio, video and neuro-physiological signals, collected with the aim of studying information exchanges and common ground instantiation in conversation in a new, more indepth way. We recorded conversations from 28 dyads (56 participants) during 30 minutes experiments where subjects were first tasked to collaborate on a joint information game, then freely drifted to the topic of their choice. During each session, audio and video were captured, along with the participants' neural signal (EEG with Biosemi 64) and their electrophysiological activity (with Empatica-E4). The paper situates this new type of resources in the literature, presents the experimental setup and describes the different kinds of annotations considered for the corpus

Larynx under ultra-high subglottal pressure: measure of contact force between vocal folds in excised human larynges

International audienceObjective: Subglottal pressure is often considered as a clue of vocal abuse, and this parameter is supposed to beat the origin of the phonotraumatism. This study is based on experiments on excised human larynges. Theobjective of this study was to analyze the contact pressure between the vocal folds during phonation and itsrelation with subglottal pressure until very high values.Material and methods: 7 human excised larynges were set on the experimental test-bench. The vocal foldadduction was determined before the tests, using concomitant arytenoid adduction and membranous vocal foldmedialization with Montgomery implants. The subglottal pressure (SGP) increased from 0 to 200 hPa. Thecontact pressure was measured with a pressure sensor placed between the vocal folds, the tracheal airflow andsubglottal pressure were measured 1 cm under the glottis, the electroglottography (EGG) was recorded, as wellas the audio signal (microphone distance: 15cm from the larynx).Results: At the phonation threshold, contact pressure appeared at the same time as the first activity of EGG,before the onset of the glottal cycle, then rapidly increased until a plateau. The maximal values of the contactpressure were very variable between the larynges (range: 0,7-12kPa). This contact pressure was not proportionalto the subglottal pressure.Discussion: These results question the role of subglottal pressure as the main factor of phonotrauma in vocalabuse when glottal configuration is constant. The adduction forces between vocal folds may be more relevant butvery difficult to measure in patients

SMYLE: A new multimodal resource of talk-in-interaction including neuro-physiological signal

International audienceThis article presents the SMYLE corpus, the first multimodal corpus in French (16h) including neuro-physiological data from 60 participants engaged in face-to-face storytelling (8.2h) and free conversation tasks (7.8h). The originality of this corpus lies first in the fact that it bears all modalities, precisely synchronized and second in the addition for the first time at this scale of neuro-physiological modalities. It constitutes the first corpus of this size offering the opportunity to investigate cognitive characteristics of spontaneous conversation including at the brain level. The storytelling task comprises two conditions: a storyteller talking with a "normal" or a "distracted" listener. Contrasting normal and disrupted conversations allows to study at a behavioral, linguistic and cognitive levels the complex characteristics and organization of conversations. In this article, we present first the methodology developed to acquire and synchronize the different sources and types of signal. In a second part, we detail the large set of automatic, semi-automatic and manual annotations of the complete dataset. In a last section, we illustrate one application of the corpus by providing preliminary analyses of the annotated data, that reveal the impact of distracted listener’s on his/her feedbacks and the quality of the narration

Singing excised human larynges: Investigating aerodynamical and biomechanical control of phonation

International audienceThe fundamental frequency of the singing voice is controlled by biomechanical and aerodynamical laryngeal parameters. In this ex vivo study, we have independently simulated several of these control parameters, namely subglottal pressure, vocal fold extension and arytenoid compression, using excised human larynges in order to investigate the fluid-structure relationship between subglottal pressure and fundamental frequency. A subglottal supply of compressed air was used to induce vocal fold self-oscillation in one female larynx (96 years) tested directly after dissection (<72 hours post-mortem), and seven frozen larynges (4 female, and 3 male, aged 81±11 and 77±9 years respectively) tested after thawing. Each of the tested control parameters results in a voice with similar dynamic and frequency ranges albeit with a non-linear relationship between subglottal pressure and fundamental frequency, evidenced by pitch jumps and hysteresis. Thus in principle, control of the fundamental frequency of the voice over its entire range can be achieved by using any of the laryngeal parameters in isolation. However, performance of a smooth glissando or a messa di voce would require fine control of multiple parameters “in concert” to dynamically compensate for the non-linearities and avoid pitch jumps.Furthermore, application of a subglottal source of pressurised air causes a narrowing of the aryepiglottic tube due to the Bernoulli force and in many cases self-oscillation of the ventricular and/or aryepiglottic folds occurs unless the supraglottic structure is held separate. Thus, further study is needed to effectively simulate the biomechanical control of the supraglottic laryngeal structures ex vivo

A New Beam Loss Monitor Concept Based on Fast Neutron Detection and Very Low Photon Sensitivity

International audienceSuperconductive accelerators may emit X-rays and Gammas mainly due to high electric fields applied on the superconductive cavity surfaces. Indeed, electron emissions will generate photons when electrons impinge on some material. Their energies depend on electron energies, which can be strongly increased by the cavity radio frequency power when it is phase-correlated with the electrons. Such photons present a real problem for Beam Loss Monitor (BLM) systems since no discrimination can be made between cavity contributions and beam loss contributions. Therefore, a new BLM is proposed which is based on gaseous Micromegas detectors, highly sensitive to fast neutrons, not to thermal ones and mostly insensitive to X-rays and Gammas. This detector uses Polyethylene for neutron moderation and the detection is achieved using a 10B or 10B4C converter film with a Micromegas gaseous amplification. Simulations show that detection efficiencies &gt; 8 % are achievable for neutrons with energies between 1 eV and 10 MeV

Caractérisation expérimentale multi-échelle et interdisciplinaire des plis vocaux

National audienc

Caractérisation expérimentale multi-échelle et interdisciplinaire des plis vocaux

National audienc

The Badalona Corpus An Audio, Video and Neuro-Physiological Conversational Dataset

International audienceWe present in this paper the first natural conversational corpus recorded with all modalities and neuro-physiological signals. Five dyads (10 participants, Spanish native speakers) have been recorded three times, during three sessions (about 30 minutes each) with 4 days interval. During each session, audio and video are captured as well as the neural signal (EEG with Emotiv-EPOC) and the electro-physiological one (with Empatica-E4). This resource is original in several respects. Technically, it is the first one gathering all these types of data in a natural conversation situation. Moreover, the recording of the same dyads at different periods opens the door to new longitudinal investigations such as the evolution of interlocutors' alignment over time. The paper situates this new type of resources in the literature, presents the experimental setup and describes different annotations enriching the corpus