An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers
equipped with 16 bolometric Ge light detectors, aiming at optimization of
detector structure for CROSS and CUPID ...double-beta decay experiments, was
constructed and tested in a low-background pulse-tube-based cryostat at the
Canfranc underground laboratory in Spain. Performance of the scintillating
bolometers was studied depending on the size of phonon NTD-Ge sensors glued to
both LMO and Ge absorbers, shape of the Ge light detectors (circular vs.
square, from two suppliers), in different light collection conditions (with and
without reflector, with aluminum coated LMO crystal surface). The scintillating
bolometer array was operated over 8 months in the low-background conditions
that allowed to probe a very low, $\mu$Bq/kg, level of the LMO crystals
radioactive contamination by $^{228}$Th and $^{226}$Ra.
Damage caused by fretting interests many industrial areas. Thus an apparatus has been designed allowing one to study fretting fatigue and fretting wear damage between two hertzian contacting samples ...submitted to vibrations at high frequency. A closed loop feedback system is used to maintain amplitude and position, thus allowing the machine to have a precise relocation of the stylus and to keep this position during test. Amplitude closed loop system provides either a constant amplitude, displacement, force, acceleration or speed during a test over a wide frequency range. This machine has been successfully applied to both fretting fatigue tests and fretting wear tests. Moreover, the apparatus design allows us to study the effect of the environment on freitting damage. Air, distilled water or liquid nitrogen are the main media to which contacts have been subjected.
We report on the development of thermal detectors based on large-size tellurium dioxide crystals (45x45x45 mm), containing tellurium enriched in \(^{130}\)Te to about 91%, for the CROSS double-beta ...decay experiment. A powder used for the crystals growth was additionally purified by the directional solidification method, resulting in the reduction of the concentration of impurities by a factor 10, to a few ppm of the total concentration of residual elements (the main impurity is Fe). The purest part of the ingot (the first ~200 mm, about 80% of the total length of the cylindrical part of the ingot) was determined by scanning segregation profiles of impurities and used for the \(^{130}\)TeO\(_2\) powder production with no evidence of re-contamination. The crystal growth was verified with precursors produced from powder with natural Te isotopic composition, and two small-size (20x20x10 mm) samples were tested at a sea-level laboratory showing high bolometric and spectrometric performance together with acceptable \(^{210}\)Po content (below 10 mBq/kg). This growth method was then applied for the production of six large cubic \(^{130}\)TeO\(_2\) crystals and 4 of them were taken randomly to be characterized at the Canfranc underground laboratory, in the CROSS-dedicated low-background cryogenic facility. Two \(^{130}\)TeO\(_2\) samples were coated with a thin, \(O\)(100 nm), metal film in form of Al layer (on 4 sides) or AlPd grid (on a single side) to investigate the possibility to tag surface events by pulse-shape discrimination. Similarly to the small natural precursors, large-volume \(^{130}\)TeO\(_2\) bolometers show high performance and even better internal purity (\(^{210}\)Po activity \(\sim\) 1 mBq/kg, while activities of \(^{228}\)Th and \(^{226}\)Ra are below 0.01 mBq/kg), satisfying requirements for the CROSS and, potentially, next-generation experiments.
In preparation to the CROSS \(2\beta\) decay experiment, we installed a new detector suspension with magnetic dumping inside a pulse-tube cryostat of a dedicated low-background facility at the LSC ...(Spain). The suspension was tested with two scintillating bolometers based on large-volume 116CdWO4 (CWO-enr) and Li2MoO4 (LMO) crystals. The former, a reference device, was used for testing new noise conditions and for comparing bolometric performance of an advanced Li2MoO4 crystal developed in the framework of the CLYMENE project, in view of next-generation double-beta decay experiments like CUPID. We cooled down detectors to 15 mK and achieved high performance for all tested devices. In particular both CWO-enr and LMO bolometers demonstrated the energy resolution of 6 keV FWHM for the 2.6 MeV gamma quanta, among the best for thermal detectors based on such compounds. The baseline noise resolution (FWHM) of the CWO-enr detector was improved by 2 keV, compared to the best previous measurement of this detector in the CROSS facility, while the noise of the Ge-based optical bolometer was improved by a factor 2, to 100 eV FWHM. Despite of the evident progress in the improving of noise conditions of the set-up, we see high-frequency harmonics of a pulse-tube induced noise, suggesting a noise pick-up by cabling. Another Ge light detector was assisted with the signal amplification exploiting the Neganov-Trofimov-Luke effect, which allowed to reach 20 eV FWHM noise resolution by applying 60 V electrode bias. Highly-efficient particle identification was achieved with both detectors, despite a low scintillation efficiency of the LMO material. The radiopurity level of the LMO crystal is rather high; only traces of 210Po and 226Ra were detected (0.1 mBq/kg each), while the 228Th activity is expected to be at least an order of magnitude lower, as well as a 40K activity is found to be < 6 mBq/kg.
An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers equipped with 16 bolometric Ge light detectors, aiming at optimization of detector structure for CROSS and CUPID ...double-beta decay experiments, was constructed and tested in a low-background pulse-tube-based cryostat at the Canfranc underground laboratory in Spain. Performance of the scintillating bolometers was studied depending on the size of phonon NTD-Ge sensors glued to both LMO and Ge absorbers, shape of the Ge light detectors (circular vs. square, from two suppliers), in different light collection conditions (with and without reflector, with aluminum coated LMO crystal surface). The scintillating bolometer array was operated over 8 months in the low-background conditions that allowed to probe a very low, \(\mu\)Bq/kg, level of the LMO crystals radioactive contamination by \(^{228}\)Th and \(^{226}\)Ra.
During a 3-year period, 62 dyslexic children have been investigated in the Neuropediatric Unit of Montpellier's U (France). An evaluation of intellectual abilities, of oral language comprehension & ...production, & of reading difficulties has been performed, together with psychological & cognitive functions studies (auditivo-verbal & phonological perception, visual discrimination, attention, & memory). The analysis of these cases underlines the heterogeneity of developmental dyslexias, the frequency of previous oral language difficulties, & the inadequacy of the therapeutic approach of these patients. 1 Figure, 31 References. Adapted from the source document
The authors report 10 cases of epileptic patients with the onset in childhood of the clinical and EEG features of cryptogenic generalized epilepsy which evolved into frontal epilepsy, confirmed by ...the clinical and EEG features and was associated with a frontal syndrome. CT-scan and MRI showed mild atrophy in the frontal area, while SPECT showed a decrease in the frontal blood flow in 70% of the cases. The authors consider that frontal epilepsy may mimic generalized epilepsy.
Eighty one patients with inoperable non-small cell lung carcinoma (NSCLC) were entered in a randomized phase II trial comparing split-dose irradiation alone to combined treatment radiotherapy and ...polychemotherapy (C.A.P. + V.D.S.). The quality of life and the survival of the patients were studied. We have defined three classes of quality of life responses based on the time elapsed before the performance status index drops. A higher quality of life failure rate was observed in the combined treatment group (p non-significant) but the time elapsed before the Karnofsky index drops is longer in the combined treatment group for the quality of life "no change" subgroup (p = 0.15). Survival and quality adjusted survival are similar in both treatment groups. The same conclusion holds for retrospective stratified treatment groups. The results of the study are presented according to the decision tree theory. We conclude that as far as the quality of life is concerned, polychemotherapy combined with the particular split-dose irradiation schedule used is an effective treatment of inoperable NSCLC. Its efficiency is comparable to, but not better than, the same radiotherapy schedule alone taken as a reference baseline.
The introduction of air gaps in multi-level Cu interconnect stacks will be mandatory to achieve high performance signal propagation characteristics for advanced technology node. In this paper, air ...cavities were successfully introduced in a two-metal level interconnect stack using respectively a polymer and a sacrificial SiO 2 at via and metal levels. Combined with a diluted HF chemistry and specific HF diffusion pathways patterned in a SiC liner, the ability to localize the introduction of air cavities in a dedicated large electrical area was demonstrated. Electrical characteristics and mechanical simulations demonstrated the interest of the approach with respect to ultra-low K material integration issues.
