arXiv subjects

M. Deveaux

Publications and source records attributed to M. Deveaux.

35 records · Page 2Linked to original sources

arXiv2019

Observations on MIMOSIS-0, the first dedicated CPS prototype for the CBM MVD

The Micro Vertex Detector (MVD) of the future Compressed Baryonic Matter (CBM) experiment at FAIR will have to provide a spatial precision of $\sim 5~\rm μm$ in combination with a material budget of 0.3\% - 0.5\% X$_0$ for a full detector station. Simultaneously, it will have to handle the rate and radiation load of operating the fixed target experiment at an average collision rate of 100 kHz (4 - 10 AGeV Au+Au collisions) or 10 MHz (up to 28 GeV p-A collisions). The harsh requirements call for a dedicated detector technology, which is the next generation CMOS Monolithic Active Pixel Sensor MIMOSIS. We report about the requirements for the sensor, introduce the design approach being followed to cope with it and show first test results from a first sensor prototype called MIMOSIS-0 .

physics.ins-det↗

arXiv2019

Measurements of production and inelastic cross sections for $\mbox{p}+\mbox{C}$, $\mbox{p}+\mbox{Be}$, and $\mbox{p}+\mbox{Al}$ at 60 GeV/$c$ and $\mbox{p}+\mbox{C}$ and $\mbox{p}+\mbox{Be}$ at 120 GeV/$c$

This paper presents measurements of production cross sections and inelastic cross sections for the following reactions: 60 GeV/$c$ protons with C, Be, Al targets and 120 GeV/$c$ protons with C and Be targets. The analysis was performed using the NA61/SHINE spectrometer at the CERN SPS. First measurements were obtained using protons at 120 GeV/$c$, while the results for protons at 60 GeV/$c$ were compared with previously published measurements. These interaction cross section measurements are critical inputs for neutrino flux prediction in current and future accelerator-based long-baseline neutrino experiments.

hep-ex↗

arXiv2019

Measurement of $ϕ$ meson production in p+p interactions at 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS

Results on $ϕ$ meson production in inelastic p+p collisions at CERN SPS energies are presented. They are derived from data collected by the NA61/SHINE fixed target experiment, by means of invariant mass spectra fits in the $ϕ\to K^+K^-$ decay channel. They include the first ever measured double differential spectra of $ϕ$ mesons as a function of rapidity $y$ and transverse momentum $p_T$ for proton beam momenta of 80 GeV/c and 158 GeV/c, as well as single differential spectra of $y$ or $p_T$ for beam momentum of 40 GeV/c. The corresponding total $ϕ$ yields per inelastic p+p event are obtained. These results are compared with existing data on $ϕ$ meson production in p+p collisions. The comparison shows consistency but superior accuracy of the present measurements. The emission of $ϕ$ mesons in p+p reactions is confronted with that occurring in Pb+Pb collisions, and the experimental results are compared with model predictions. It appears that none of the considered models can properly describe all the experimental observables.

nucl-ex↗

arXiv2019

Measurements of $π^{\pm}$, $K^{\pm}$ and proton yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

Measurements of the $π^{\pm}$, $K^{\pm}$, and proton double differential yields emitted from the surface of the 90-cm-long carbon target (T2K replica) were performed for the incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS using data collected during 2010 run. The double differential $π^{\pm}$ yields were measured with increased precision compared to the previously published NA61/SHINE results, while the $K^{\pm}$ and proton yields were obtained for the first time. A strategy for dealing with the dependence of the results on the incoming proton beam profile is proposed. The purpose of these measurements is to reduce significantly the (anti)neutrino flux uncertainty in the T2K long-baseline neutrino experiment by constraining the production of (anti)neutrino ancestors coming from the T2K target.

hep-ex↗

arXiv2017

Measurements of $π^\pm$, K$^\pm$, p and $\bar{\textrm{p}}$ spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS

Measurements of inclusive spectra and mean multiplicities of $π^\pm$, K$^\pm$, p and $\bar{\textrm{p}}$ produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ($\sqrt{s} = $ 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter.

nucl-ex↗

arXiv2017

Radiation damage caused by cold neutrons in boron doped CMOS active pixel sensors

CMOS Monolithic Active Pixel Sensors (MAPS) are considered as an emerging technology in the field of charged particle tracking. They will be used in the vertex detectors of experiments like STAR, CBM and ALICE and are considered for the ILC and the tracker of ATLAS. In those applications, the sensors are exposed to sizeable radiation doses. While the tolerance of MAPS to ionizing radiation and fast hadrons is well known, the damage caused by low energy neutrons was not studied so far. Those slow neutrons may initiate nuclear fission of $^{10}$B dopants found in the B-doped silicon active medium of MAPS. This effect was expected to create an unknown amount of radiation damage beyond the predictions of the NIEL (Non Ionizing Energy Loss) model for pure silicon. We estimate the impact of this effect by calculating the additional NIEL created by this fission. Moreover, we show first measured data for CMOS sensors which were irradiated with cold neutrons. The empirical results contradict the prediction of the updated NIEL model both, qualitatively and quantitatively: The sensors irradiated with slow neutrons show an unexpected and strong acceptor removal, which is not observed in sensors irradiated with MeV neutrons.

physics.ins-det↗

arXiv2017

Measurement of Meson Resonance Production in $π^{-} + $C Interactions at SPS energies

We present measurements of $ρ^0$, $ω$ and K$^{*0}$ spectra in $π^{-} + $C production interactions at 158 GeV/c and $ρ^0$ spectra at 350 GeV/c using the NA61/SHINE spectrometer at the CERN SPS. Spectra are presented as a function of the Feynman's variable $x_\text{F}$ in the range $0 < x_\text{F} < 1$ and $0 < x_\text{F} < 0.5$ for 158 GeV/c and 350 GeV/c respectively. Furthermore, we show comparisons with previous measurements and predictions of several hadronic interaction models. These measurements are essential for a better understanding of hadronic shower development and for improving the modeling of cosmic ray air showers.

nucl-ex↗

arXiv2017

Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p+p interactions at the CERN Super Proton Synchrotron

Results on two-particle $ΔηΔϕ$ correlations in inelastic p+p interactions at 20, 31, 40, 80, and 158~GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the EPOS and UrQMD models.

nucl-ex↗

arXiv2016

Measurements of $π^{\pm}$ differential yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

Measurements of particle emission from a replica of the T2K 90 cm-long carbon target were performed in the NA61/SHINE experiment at CERN SPS, using data collected during a high-statistics run in 2009. An efficient use of the long-target measurements for neutrino flux predictions in T2K requires dedicated reconstruction and analysis techniques. Fully-corrected differential yields of $π^\pm$-mesons from the surface of the T2K replica target for incoming 31 GeV/c protons are presented. A possible strategy to implement these results into the T2K neutrino beam predictions is discussed and the propagation of the uncertainties of these results to the final neutrino flux is performed.

hep-ex↗

arXiv2016

On drift fields in CMOS Monolithic Active Pixel Sensors with point-like collection diodes

- Paper withdrawn by the author - CMOS Monolithic Active Pixel Sensors for charged particle tracking are considered as technology for numerous experiments in heavy ion and particle physics. To match the requirements for those applications in terms of tolerance to non-ionizing radiation, it is being tried to deplete the sensitive volume of the, traditionally non-depleted, silicon sensors. We study the feasibility of this approach for the common case that the collection diodes of the pixel are small as compared to the pixel pitch. An analytic equation predicting the thickness of the depletion depth and the capacity of this point-like junction is introduced. We find that the predictions of this equations differs qualitatively from the usual results for flat PN junctions and that $dC/dU$-measurements are not suited to measure the depletion depth of diodes with point-like geometry. The predictions of the equation is compared with measurements on the depletion depth of CMOS sensors, which were carried out with a novel measurement protocol. It is found that the equation and the measurement results match with each other. By comparing our findings with TCAD simulations, we find that precise simulation models matches the empirical findings while simplified models overestimate the depletion depth dramatically. A potential explanation for this finding is introduced and the consequences for the design of CMOS sensors are discussed.

physics.ins-det↗

arXiv2016

Multiplicity and transverse momentum fluctuations in inelastic proton-proton interactions at the CERN Super Proton Synchrotron

Measurements of multiplicity and transverse momentum fluctuations of charged particles were performed in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c beam momentum. Results for the scaled variance of the multiplicity distribution and for three strongly intensive measures of multiplicity and transverse momentum fluctuations \$Δ[P_{T},N]\$, \$Σ[P_{T},N]\$ and \$Φ_{p_T}\$ are presented. For the first time the results on fluctuations are fully corrected for experimental biases. The results on multiplicity and transverse momentum fluctuations significantly deviate from expectations for the independent particle production. They also depend on charges of selected hadrons. The string-resonance Monte Carlo models EPOS and UrQMD do not describe the data. The scaled variance of multiplicity fluctuations is significantly higher in inelastic p+p interactions than in central Pb+Pb collisions measured by NA49 at the same energy per nucleon. This is in qualitative disagreement with the predictions of the Wounded Nucleon Model. Within the statistical framework the enhanced multiplicity fluctuations in inelastic p+p interactions can be interpreted as due to event-by-event fluctuations of the fireball energy and/or volume.

hep-ex↗

arXiv2016

Effect and suppression of parasitic surface damage in neutron irradiated CMOS Monolithic Active Pixel Sensors

CMOS Monolithic Active Pixel Sensors (MAPS) were chosen as sensor technology for the vertex detectors of STAR, CBM and the upgraded ALICE-ITS. They also constitute a valuable option for tracking devices at future e+e- colliders. Those applications require a substantial tolerance to both, ionizing and non-ionizing radiation. To allow for a focused optimization of the radiation tolerance, prototypes are tested by irradiating the devices either with purely ionizing radiation (e.g. soft X-rays) or the most pure sources of non-ionizing radiation available (e.g. reactor neutrons). In the second case, it is typically assumed that the impact of the parasitic $γ$-rays found in the neutron beams is negligible. We checked this assumption by irradiating MAPS with $γ$-rays and comparing the radiation damage generated with the one in neutron irradiated sensors. We conclude that the parasitic radiation doses may cause non-negligible radiation damage. Based on the results we propose a procedure to recognize and to suppress the effect of the related parasitic ionizing radiation damage.

physics.ins-det↗

arXiv2016

Production of $Λ$ hyperons in inelastic p+p interactions at 158 GeV/$c$

Inclusive production of $Λ$-hyperons was measured with the large acceptance NA61/SHINE spectrometer at the CERN SPS in inelastic p+p interactions at beam momentum of 158~\GeVc. Spectra of transverse momentum and transverse mass as well as distributions of rapidity and x$_{_F}$ are presented. The mean multiplicity was estimated to be $0.120\,\pm0.006\;(stat.)\,\pm 0.010\;(sys.)$. The results are compared with previous measurements and predictions of the EPOS, UrQMD and FRITIOF models.

hep-ex↗

arXiv2016

Measurements of $π^\pm$, $K^\pm$, $K^0_S$, $Λ$ and proton production in proton-carbon interactions at 31 GeV/$c$ with the NA61/SHINE spectrometer at the CERN SPS

Measurements of hadron production in p+C interactions at 31 GeV/c are performed using the NA61/ SHINE spectrometer at the CERN SPS. The analysis is based on the full set of data collected in 2009 using a graphite target with a thickness of 4% of a nuclear interaction length. Inelastic and production cross sections as well as spectra of $π^\pm$, $K^\pm$, p, $K^0_S$ and $Λ$ are measured with high precision. These measurements are essential for improved calculations of the initial neutrino fluxes in the T2K long-baseline neutrino oscillation experiment in Japan. A comparison of the NA61/SHINE measurements with predictions of several hadroproduction models is presented.

hep-ex↗

arXiv2010

Development of ultra-light pixelated ladders for an ILC vertex detector

The development of ultra-light pixelated ladders is motivated by the requirements of the ILD vertex detector at ILC. This paper summarizes three projects related to system integration. The PLUME project tackles the issue of assembling double-sided ladders. The SERWIETE project deals with a more innovative concept and consists in making single-sided unsupported ladders embedded in an extra thin plastic enveloppe. AIDA, the last project, aims at building a framework reproducing the experimental running conditions where sets of ladders could be tested.

physics.ins-det↗

arXiv2009

Radiation Tolerance of CMOS Monolithic Active Pixel Sensors with Self-Biased Pixels

CMOS Monolithic Active Pixel Sensors (MAPS) are proposed as a technology for various vertex detectors in nuclear and particle physics. We discuss the mechanisms of ionizing radiation damage on MAPS hosting the the dead time free, so-called self bias pixel. Moreover, we discuss radiation hardened sensor designs which allow operating detectors after exposing them to irradiation doses above 1 Mrad

physics.ins-det↗

arXiv2009

Design considerations for the Micro Vertex Detector of the Compressed Baryonic Matter experiment

The CBM experiment will investigate heavy-ion collisions at beam energies from 8 to 45 AGeV at the future accelerator facility FAIR. The goal of the experiment is to study the QCD phase diagram in the region of moderate temperatures and highest net-baryon densities in search of the first-order phase transition from confined to deconfined matter at the QCD critical point. To do so, CBM aims to measure rare hadronic, leptonic and photonic probes among them open charm. In order to reject the rich background generated by the heavy ion collisions, a micro vertex detector (MVD) providing an unprecedented combination of high rate capability and radiation hardness, very light material budget and excellent granularity is required. In this work, we will present and discuss the concept of this detector.

nucl-ex↗