SiLC R&D: Design, present status and perspectives Lozano, M.; Orava, R.; van Remortel, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2007, Volume:
579, Issue:
2
Journal Article
Peer reviewed
Open access
This paper briefly describes the main R&D objectives that are undertaken within the international R&D collaboration SiLC aiming to build the next generation of silicon tracking devices especially in ...the case of the ILC. Firstly, motivation to use silicon detectors in the tracker is explained. Then basic aspects of the design and solutions proposed are described (sensors, front-end electronics, mechanics, alignment). First results from the lab and beam test of the front-end chips and module prototypes built are shown.
Intense lasers interacting with dense targets accelerate relativistic electron beams, which transport part of the laser energy into the target depth. However, the overall laser-to-target energy ...coupling efficiency is impaired by the large divergence of the electron beam, intrinsic to the laser-plasma interaction. Here we demonstrate that an efficient guiding of MeV electrons with about 30 MA current in solid matter is obtained by imposing a laser-driven longitudinal magnetostatic field of 600 T. In the magnetized conditions the transported energy density and the peak background electron temperature at the 60-μm-thick target's rear surface rise by about a factor of five, as unfolded from benchmarked simulations. Such an improvement of energy-density flux through dense matter paves the ground for advances in laser-driven intense sources of energetic particles and radiation, driving matter to extreme temperatures, reaching states relevant for planetary or stellar science as yet inaccessible at the laboratory scale and achieving high-gain laser-driven thermonuclear fusion.
We report experimental results on relativistic electron beam (REB) transport in a set of cold and shock-heated carbon samples using the high-intensity kilojoule-class OMEGA EP laser. The REB energy ...distribution and transport were diagnosed using an electron spectrometer and x-ray fluorescence measurements from a Cu tracer buried at the rear side of the samples. The measured rear REB density shows brighter and narrower signals when the targets were shock-heated. Hybrid PIC simulations using advanced resistivity models in the target warm-dense-matter (WDM) conditions confirm this observation. We show that the resistivity response of the media, which governs the self-generated resistive fields, is of paramount importance to understand and correctly predict the REB transport.
Background
Transient and persistent acute kidney injury (AKI) could share similar physiopathological mechanisms. The objective of our study was to assess prognostic impact of AKI duration on ICU ...mortality.
Design
Retrospective analysis of a prospective database via cause-specific model, with 28-day ICU mortality as primary end point, considering discharge alive as a competing event and taking into account time-dependent nature of renal recovery. Renal recovery was defined as a decrease of at least one KDIGO class compared to the previous day.
Setting
23 French ICUs.
Patients
Patients of a French multicentric observational cohort were included if they suffered from AKI at ICU admission between 1996 and 2015.
Intervention
None.
Results
A total of 5242 patients were included. Initial severity according to KDIGO creatinine definition was AKI stage 1 for 2458 patients (46.89%), AKI stage 2 for 1181 (22.53%) and AKI stage 3 for 1603 (30.58%). Crude 28-day ICU mortality according to AKI severity was 22.74% (
n
= 559), 27.69% (
n
= 327) and 26.26% (
n
= 421), respectively. Renal recovery was experienced by 3085 patients (58.85%), and its rate was significantly different between AKI severity stages (
P
< 0.01). Twenty-eight-day ICU mortality was independently lower in patients experiencing renal recovery CSHR 0.54 (95% CI 0.46–0.63),
P
< 0.01. Lastly, RRT requirement was strongly associated with persistent AKI whichever threshold was chosen between day 2 and 7 to delineate transient from persistent AKI.
Conclusions
Short-term renal recovery, according to several definitions, was independently associated with higher mortality and RRT requirement. Moreover, distinction between transient and persistent AKI is consequently a clinically relevant surrogate outcome variable for diagnostic testing in critically ill patients.
In this paper we describe the physical processes that lead to the generation of giant electromagnetic pulses (GEMPs) at powerful laser facilities. Our study is based on experimental measurements of ...both the charging of a solid target irradiated by an ultra-short, ultra-intense laser and the detection of the electromagnetic emission in the GHz domain. An unambiguous correlation between the neutralization current in the target holder and the electromagnetic emission shows that the source of the GEMP is the remaining positive charge inside the target after the escape of fast electrons accelerated by the ultra-intense laser. A simple model for calculating this charge in the thick target case is presented. From this model and knowing the geometry of the target holder, it becomes possible to estimate the intensity and the dominant frequencies of the GEMP at any facility.
Thermoset-based composites exhibit irreversible distortions during manufacturing, which are detrimental to the assembly and then to the mechanical integrity. The optimal mold geometry can be ...determined by numerical simulation such that the produced composite component matches the target design. A simple mold compensation methodology as well as an all-around experimental validation are proposed for a doubly-curved part made of a carbon fiber reinforced composite. Non-compensated and compensated parts are processed in order to quantify the gain obtained by the compensation procedure and to validate the method. The spring-in is reduced by more than 90% and the overall distortions are reduced by about 70%.
A finite element procedure is developed for the computation of the thermoelastic properties of textile composites with complex and compact two- and three-dimensional woven reinforcement ...architectures. The purpose of the method is to provide estimates of the properties of the composite with minimum geometrical modeling effort. The software TexGen is used to model simplified representations of complex textiles. This results in severe yarn penetrations, which prevent conventional meshing. A non-conformal meshing strategy is adopted, where the mesh is refined at material interfaces. Penetrations are mitigated by using an original local correction of the material properties of the yarns to account for the true fiber content. The method is compared to more sophisticated textile modeling approaches and successfully assessed towards experimental data selected from the literature.
PDF
