In the last few years, the 28 nm CMOS technology has raised interest in the High Energy Physics community for the design and implementation of readout integrated circuits for high granularity ...position sensitive detectors. This work is focused on the characterization of the 28 nm CMOS node with a particular focus on the analog performance. Small signal characteristics and the behavior of the white and 1/f noise components are studied as a function of the device polarity, dimensions, and bias conditions to provide guidelines for minimum noise design of front-end electronics. Comparison with data extracted from previous CMOS generations are also presented to assess the performance of the technology node under evaluation.
The coherence of free-electron laser (FEL) radiation has so far been accessed mainly through first and second order correlation functions. Instead, we propose to reconstruct the energy state ...occupation number distribution of FEL radiation, avoiding the photo-counting drawbacks with high intensities, by means of maximum likelihood techniques based on the statistics of no-click events. Though the ultimate goal regards the FEL radiation statistical features, the interest of the proposal also resides in its applicability to any process of harmonic generation from a coherent light pulse, ushering in the study of the preservation of quantum features in general non-linear optical processes.
The linear front-end is the analog processor chosen for the final integration into the pixel readout chip for the high-luminosity upgrade of the CMS experiment at the large hadron collider. The ...front-end has been included in the RD53A chip, designed by the CERN RD53 collaboration and submitted in 2017. An optimized version of the front-end has been designed, submitted, and tested in the framework of the RD53B developments. The optimization is mainly concerned with the time-walk performance of the front-end and with its threshold tuning capabilities. The article describes in detail such design improvements together with the results from the characterization of a small prototype chip including a 16 <inline-formula> <tex-math notation="LaTeX">\times </tex-math></inline-formula> 16 pixel matrix featuring both the RD53A and RD53B versions of the front-end. Test results show a significant reduction, about 10 ns for input signals close to the threshold, of the time-walk in the RD53B front-end, featuring a threshold dispersion smaller than 65 electrons r.m.s. after exposure to a total ionizing dose of 1 Grad of X-rays.
Arrays of single photon avalanche diodes (SPADs) fabricated in a 150 nm CMOS technology have been exposed to neutrons up to fluences of about <inline-formula> <tex-math notation="LaTeX">4.3 \times ...10^{10}~1 </tex-math></inline-formula> MeV neutron equivalent cm<inline-formula> <tex-math notation="LaTeX">^{-2} </tex-math></inline-formula>, with fluxes around <inline-formula> <tex-math notation="LaTeX">3 \times 10^{6}~1 </tex-math></inline-formula> MeV neutron equivalent cm<inline-formula> <tex-math notation="LaTeX">^{-2}\text{s}^{-1} </tex-math></inline-formula>. Dark count rate (DCR) was monitored during irradiation and for some time, from 5 to 23 min, depending on the irradiation step, at the end of the irradiation interval to investigate the dynamics of defect formation and short-term annealing. Measurements were performed both on single- and on dual-layer devices, where SPAD arrays are face to face bonded and read out in coincidence. A range of different DCR behaviors were detected after single neutron interaction with the device substrate, including in particular partial performance recovery following a logarithmic relaxation process, but also damped oscillation phenomena, sudden step-shaped changes, and the emergence of RTS-like fluctuations, pointing to different defect reordering dynamics.
A front-end channel prototype for pixel detectors has been designed for the upgrades of the HL-LHC experiments. The circuit is based on a Krummenacher feedback network to continuously reset the ...charge sensitive amplifier and on a fast threshold discriminator to implement a time-over-threshold (ToT) method and perform amplitude measurement. The front-end circuit was developed in a 65 nm CMOS technology and takes an overall area not exceeding 1250 μm 2 , i.e., half of the overall pixel area. The current consumption per channel is around 4 μA at VDD = 1.2 V. A very small charge sensitivity dispersion was detected in the set of characterized samples. An equivalent noise charge of 120 e - was found for a detector capacitance of 100 fF. The response of the channel is compatible with the speed requirements of the foreseen application in the innermost layers of the CMS pixel detector.
Excessive daytime sleepiness is common in Parkinson's disease and has been associated with Parkinson's disease-related dementia. Narcoleptic features have been observed in Parkinson's disease ...patients with excessive daytime sleepiness and hypocretin cell loss has been found in the hypothalamus of Parkinson's disease patients, in association with advanced disease. However, studies on cerebrospinal fluid levels of hypocretin-1 (orexin A) in Parkinson's disease have been inconclusive. Reports of sleep studies in Parkinson's disease patients with and without excessive daytime sleepiness have also been disparate, pointing towards a variety of causes underlying excessive daytime sleepiness. In this study, we aimed to measure cerebrospinal fluid hypocretin-1 levels in Parkinson's disease patients with and without dementia and to study their relationship to dementia and clinical excessive daytime sleepiness, as well as to describe potentially related sleep architecture changes. Twenty-one Parkinson's disease patients without dementia and 20 Parkinson's disease patients with dementia, along with 22 control subjects without sleep complaints, were included. Both Epworth sleepiness scale, obtained with the help of the caregivers, and mini-mental state examination were recorded. Lumbar cerebrospinal fluid hypocretin-1 levels were measured in all individuals using a radio-immunoassay technique. Additionally, eight Parkinson's disease patients without dementia and seven Parkinson's disease patients with dementia underwent video-polysomnogram and multiple sleep latencies test. Epworth sleepiness scale scores were higher in Parkinson's disease patients without dementia and Parkinson's disease patients with dementia than controls (P < 0.01) and scores >10 were more frequent in Parkinson's disease patients with dementia than in Parkinson's disease patients without dementia (P = 0.04). Cerebrospinal fluid hypocretin-1 levels were similar among groups (controls = 321.15 ± 47.15 pg/ml; without dementia = 300.99 ± 58.68 pg/ml; with dementia = 309.94 ± 65.95 pg/ml; P = 0.67), and unrelated to either epworth sleepiness scale or mini-mental state examination. Dominant occipital frequency awake was slower in Parkinson's disease patients with dementia than Parkinson's disease patients without dementia (P = 0.05). Presence of slow dominant occipital frequency and/or loss of normal non-rapid eye movement sleep architecture was more frequent among Parkinson's disease patients with dementia (P = 0.029). Thus, excessive daytime sleepiness is more frequent in Parkinson's disease patients with dementia than Parkinson's disease patients without dementia, but lumbar cerebrospinal fluid hypocretin-1 levels are normal and unrelated to severity of sleepiness or the cognitive status. Lumbar cerebrospinal fluid does not accurately reflect the hypocretin cell loss known to occur in the hypothalamus of advanced Parkinson's disease. Alternatively, mechanisms other than hypocretin cells dysfunction may be responsible for excessive daytime sleepiness and the sleep architecture alterations seen in these patients.
To cope with the challenging environment of the planned high luminosity upgrade of the Large Hadron Collider (HL-LHC), scheduled to start operation in 2029, CMS will replace its entire tracking ...system. The requirements for the tracker are largely determined by the long operation time of 10 years with an instantaneous peak luminosity of up to 7.5 × 1034cm−2s−1 in the ultimate performance scenario. Depending on the radial distance from the interaction point, the silicon sensors will receive a particle fluence corresponding to a non-ionising energy loss of up to Φeq= 3.5 × 1016cm−2. This paper focuses on planar pixel sensor design and qualification up to a fluence of Φeq = 1.4 × 1016cm−2.
For the development of appropriate planar pixel sensors an R&D program was initiated, which includes n+-p sensors on 150mm (6”) wafers with an active thickness of 150µm with pixel sizes of 100×25 µm2 and 50×50 µm2 manufactured by Hamamatsu Photonics K.K. (HPK). Single chip modules with ROC4Sens and RD53A readout chips were made. Irradiation with protons and neutrons, as well was an extensive test beam campaign at DESY were carried out. This paper presents the investigation of various assemblies mainly with ROC4Sens readout chips. It demonstrates that multiple designs fulfil the requirements in terms of breakdown voltage, leakage current and efficiency. The single point resolution for 50×50 µm2 pixels is measured as 4.0µm for non-irradiated samples, and 6.3µm after irradiation to Φeq = 7.2 × 1015cm−2.
The liver transplantation procedure, in addition to its prolonged surgical time, also predisposes to complications such as changes in respiratory mechanics, lung volumes, and gas exchange.
This study ...aims to verify if clinical factors related to the recipient, namely immediate pretransplant Model for End-Stage Liver Disease (MELD) score, surgical time, and root square metric (RMS) of the diaphragmatic domes, affect the extubation time after liver transplantation.
A prospective study, with a sample collected for convenience, gathered age (years), sex (male or female), MELD score immediately prior to transplantation (without the addition of special situation scores), and surgical time and time for extubation (in minutes). The latter were obtained from the physiotherapy team records, and surface electromyography was performed within 30 minutes after elective extubation, by a single researcher, with supplemental oxygen support, maintaining SpO2 ≥ 95% and following protocol of positioning and acquisition of electromyographic signals based on the study of Oliveira et al (2012).
For the 21 patients studied, the RMS of the left dome showed a moderate-intensity correlation (−0.56) with the time of extubation, and linear multiple regression model the left dome (P = .013) and preoperative MELD score (P = .048) showed significant correlation with extubation time.
The preoperative MELD score and the RMS values of the left dome significantly correlate with the time for patient extubation after liver transplantation, showing the effect of previously acquired muscle weakness and preoperative MELD score on postoperative outcome.
This work reports on the main results from the experimental characterization of the asynchronous analog front-end integrated in a 65 nm CMOS mixed-signal chip for the readout of high granularity ...silicon pixel sensors at the high-luminosity upgrades of the ATLAS and CMS experiments. Such a mixed-signal chip has been designed and submitted in the framework of the CHIPIX65 project, funded by the Italian Institute of Nuclear Physics for the development of an advanced pixel chip in a 65 nm CMOS technology. The project fits the program of the RD53 Collaboration, whose efforts led to the submission, in August 2017, of the large scale chip RD53A, integrating, among three different front-ends, an improved version of the analog processor discussed in this work. The main performance parameters of the asynchronous analog front-end, bump-bonded to a 3D sensor developed by FBK, are discussed in this work.
PDF
