Recent Progress on 3D Silicon Detectors

3D silicon detectors, in which the electrodes penetrate the sensor bulk perpendicular to the surface, have recently undergone a rapid development from R\&D over industrialisation to their first installation in a real high-energy-physics experiment. Since June 2015, the ATLAS Insertable B-Layer is taking first collision data with 3D pixel detectors. At the same time, preparations are advancing to install 3D pixel detectors in forward trackers such as the ATLAS Forward Proton detector or the CMS-TOTEM Proton Precision Spectrometer. For those experiments, the main requirements are a slim edge and the ability to cope with non-uniform irradiation. Both have been shown to be fulfilled by 3D pixel detectors. For the High-Luminosity LHC pixel upgrades of the major experiments, 3D detectors are promising candidates for the innermost pixel layers to cope with harsh radiation environments up to fluences of $2\times10^{16}$\,n$_{eq}$/cm$^2$ thanks to their excellent radiation hardness at low operational voltages and power dissipation as well as moderate temperatures. This paper will give an overview on the recent developments of 3D detectors related to the projects mentioned above and the future plans.Comment: Proceedings of the 24th International Workshop on Vertex Detectors, 1-5 June 2015, Santa Fe, US

3D silicon pixel detectors for the ATLAS Forward Physics experiment

The ATLAS Forward Physics (AFP) project plans to install 3D silicon pixel detectors about 210 m away from the interaction point and very close to the beamline (2-3 mm). This implies the need of slim edges of about 100-200 $\mu$m width for the sensor side facing the beam to minimise the dead area. Another challenge is an expected non-uniform irradiation of the pixel sensors. It is studied if these requirements can be met using slightly-modified FE-I4 3D pixel sensors from the ATLAS Insertable B-Layer production. AFP-compatible slim edges are obtained with a simple diamond-saw cut. Electrical characterisations and beam tests are carried out and no detrimental impact on the leakage current and hit efficiency is observed. For devices without a 3D guard ring a remaining insensitive edge of less than 15 $\mu$m width is found. Moreover, 3D detectors are non-uniformly irradiated up to fluences of several 10$^{15}$ n$_{eq}$/cm$^2$ with either a focussed 23 GeV proton beam or a 23 MeV proton beam through holes in Al masks. The efficiency in the irradiated region is found to be similar to the one in the non-irradiated region and exceeds 97% in case of favourable chip-parameter settings. Only in a narrow transition area at the edge of the hole in the Al mask, a significantly lower efficiency is seen. A follow-up study of this effect using arrays of small pad diodes for position-resolved dosimetry via the leakage current is carried out.Comment: 10 pages, submitted to JINS

Blind extraction of guitar effects through blind system inversion and neural guitar effect modeling

Audio effects are an ubiquitous tool in music production due to the interesting ways in which they can shape the sound of music. Guitar effects, the subset of all audio effects focusing on guitar signals, are commonly used in popular music to shape the guitar sound to fit specific genres or to create more variety within musical compositions. Automatic extraction of guitar effects and their parameter settings, with the aim to copy a target guitar sound, has been previously investigated, where artificial neural networks first determine the effect class of a reference signal and subsequently the parameter settings. These approaches require a corresponding guitar effect implementation to be available. In general, for very close sound matching, additional research regarding effect implementations is necessary. In this work, we present a different approach to circumvent these issues. We propose blind extraction of guitar effects through a combination of blind system inversion and neural guitar effect modeling. That way, an immediately usable, blind copy of the target guitar effect is obtained. The proposed method is tested with the phaser, softclipping and slapback delay effect. Listening tests with eight subjects indicate excellent quality of the blind copies, i.e., little to no difference to the reference guitar effect

Convolutional neural networks for the classification of guitar effects and extraction of the parameter settings of single and multi-guitar effects from instrument mixes

Guitar effects are commonly used in popular music to shape the guitar sound to fit specific genres, or to create more variety within musical compositions. The sound not only is determined by the choice of the guitar effect, but also heavily depends on the parameter settings of the effect. Previous research focused on the classification of guitar effects and extraction of their parameter settings from solo guitar audio recordings. However, more realistic is the classification and extraction from instrument mixes. This work investigates the use of convolution neural networks (CNNs) for the classification and parameter extraction of guitar effects from audio samples containing guitar, bass, keyboard, and drums. The CNN was compared to baseline methods previously proposed, like support vector machines and shallow neural networks together with predesigned features. On two datasets, the CNN achieved classification accuracies 1-5% above the baseline accuracy, achieving up to 97.4% accuracy. With parameter values between 0.0 and 1.0, mean absolute parameter extraction errors of below 0.016 for the distortion, below 0.052 for the tremolo, and below 0.038 for the slapback delay effect were achieved, matching or surpassing the presumed human expert error of 0.05. The CNN approach was found to generalize to further effects, achieving mean absolute parameter extraction errors below 0.05 for the chorus, phaser, reverb, and overdrive effect. For sequentially applied combinations of distortion, tremolo, and slapback delay, the mean extraction error slightly increased from the performance for the single effects to the range of 0.05 to 0.1. The CNN was found to be moderately robust to noise and pitch changes of the background instrumentation suggesting that the CNN extracted meaningful features

Studies of irradiated AMS H35 CMOS detectors for the ATLAS tracker upgrade

Silicon detectors based on the HV-CMOS technology are being investigated as possible candidate for the outer layers of the ATLAS pixel detector for the High Luminosity LHC. In this framework the H35Demo ASIC has been produced in the 350 nm AMS technology (H35). The H35Demo chip has a large area ($18.49 \times 24.40 \, \mathrm{mm^2}$) and includes four different pixel matrices and three test structures. In this paper the radiation hardness properties, in particular the evolution of the depletion region with fluence is studied using edge-TCT on test structures. Measurements on the test structures from chips with different substrate resistivity are shown for non irradiated and irradiated devices up to a cumulative fluence of $2 \cdot 10^{15} \, \mathrm{1\,MeV\, n_{eq} / cm^{2}}$

Frequency dependent amplitude response of different couplant materials for mounting piezoelectric sensors

Non-destructive testing techniques, such as ultrasonic testing and acoustic emission analysis, commonly employ piezoelectric sensors for monitoring and detecting defects in structures. The quality of data acquired using these sensors is highly dependent on the coupling layer between the transducer and the structure's surface. In this context, this study compares the signal response of four different couplant materials, namely acrylic adhesive pads, honey, vaseline, and hot glue, applied to a steel surface. For this purpose, experiments were conducted using a laser Doppler vibrometer and acoustic emission analysis to investigate the signal transmission of the couplant materials and their impact on the signal response of a coupled piezoelectric sensor VS30-V. The repeatability of the experiments was statistically analyzed. The findings indicate that acoustic emission measurements with acrylic adhesive pads exhibited the lowest relative standard deviation of 11.4%, followed by honey (13.2%), hot glue (21.9%), and vaseline (32.1%). The investigated couplant materials exhibited different effects on the signal response of the piezoelectric sensor. Specifically, acrylic adhesive pads and hot glue demonstrated more reliable signal transmission in the frequency range of 50 kHz to 65 kHz. In contrast, honey and vaseline had better performance within the frequency range of 65 kHz and 80 kHz. Considering the frequency-dependent characteristics of signal transmission and the ease of application, acrylic adhesive pads and honey are considered the preferred couplant materials for the frequency ranges of 50 kHz to 65 kHz and 65 kHz to 80 kHz, respectively

The diagnostic value of a treadmill test in predicting lumbar spinal stenosis

Lumbar spinal stenosis is a frequent indication for spinal surgery. The predictive quality of treadmill testing and MRI for diagnostic verification is not yet clearly defined. Aim of the current study was to assess correlations between treadmill testing and MRI findings in the lumbar spine. Twenty-five patients with lumbar spinal stenosis were prospectively examined. Treadmill tests were performed and the area of the dural sac and neuroforamina was examined with MRI for the narrowest spinal segment. VAS and ODI were used for clinical assessment. The median age of the patients was 67years. In the narrowest spinal segment the median area of the dural sac was 91mm2. The median ODI was 66 per cent. The median walking distance in the treadmill test was 70m. The distance reached in the treadmill test correlated with the area of the dural sac (Spearman's ρ=0.53) and ODI (ρ=−0.51), but not with the area of the neuroforamina and VAS. The distance reached in the treadmill test predicts the grade of stenosis in MRI but has a limited diagnostic importance for the level of clinical symptoms in lumbar spinal stenosi

Increased intraoperative epidural pressure in lumbar spinal stenosis patients with a positive nerve root sedimentation sign

Purpose: The sedimentation sign (SedSign) has been shown to discriminate well between selected patients with and without lumbar spinal stenosis (LSS). The purpose of this study was to compare the pressure values associated with LSS versus non-LSS and discuss whether a positive SedSign may be related to increased epidural pressure at the level of the stenosis. Methods: We measured the intraoperative epidural pressure in five patients without LSS and a negative SedSign, and in five patients with LSS and a positive SedSign using a Codman™ catheter in prone position under radioscopy. Results: Patients with a negative SedSign had a median epidural pressure of 9mmHg independent of the measurement location. Breath and pulse-synchronous waves accounted for 1-3mmHg. In patients with monosegmental LSS and a positive SedSign, the epidural pressure above and below the stenosis was similar (median 8-9mmHg). At the level of the stenosis the median epidural pressure was 22mmHg. A breath and pulse-synchronous wave was present cranial to the stenosis, but absent below. These findings were independent of the cross-sectional area of the spinal canal at the level of the stenosis. Conclusions: Patients with LSS have an increased epidural pressure at the level of the stenosis and altered pressure wave characteristics below. We argue that the absence of sedimentation of lumbar nerve roots to the dorsal part of the dural sac in supine position may be due to tethering of affected nerve roots at the level of the stenosis

Transnational Access to Research Facilities: an EPOS service to promote multi-domain Solid Earth Sciences in Europe

Transnational access (TNA) allows cross-border, short-term and frequently free-of-charge access to world-class research facilities, to foster collaborations and exchanges of experience. Specifically, TNA aims to encourage open science and innovation and to increase the efficient and effective use of scientific infrastructure. Within EPOS, the European Plate Observing System, the Volcano Observatories and Multi-scale Laboratories communities have offered TNA to their high-quality research facilities through national and European funding. This experience has allowed the definition, design, and testing of procedures and activities needed to provide transnational access inn the EPOS context. In this paper, the EPOS community describes the main objectives for the provision of transnational access in the EPOS framework, based on previous experiences. It includes practical procedures for managing transnational access from a legal, governance, and financial perspective, and proposes logistical and technical solutions to effectively execute transnational access activities. In addition, it provides an outlook on the inclusion of new thematic communities within the TNA framework, and addresses the challenges of providing market-driven access to industry.publishedVersio

Biallelic inherited SCN8A variants, a rare cause of SCN8A‐related developmental and epileptic encephalopathy

ObjectiveMonoallelic de novo gain‐of‐function variants in the voltage‐gated sodium channel SCN8A are one of the recurrent causes of severe developmental and epileptic encephalopathy (DEE). In addition, a small number of de novo or inherited monoallelic loss‐of‐function variants have been found in patients with intellectual disability, autism spectrum disorder, or movement disorders. Inherited monoallelic variants causing either gain or loss‐of‐function are also associated with less severe conditions such as benign familial infantile seizures and isolated movement disorders. In all three categories, the affected individuals are heterozygous for a SCN8A variant in combination with a wild‐type allele. In the present study, we describe two unusual families with severely affected individuals who inherited biallelic variants of SCN8A.MethodsWe identified two families with biallelic SCN8A variants by diagnostic gene panel sequencing. Functional analysis of the variants was performed using voltage clamp recordings from transfected ND7/23 cells.ResultsWe identified three probands from two unrelated families with DEE due to biallelic SCN8A variants. Each parent of an affected individual carried a single heterozygous SCN8A variant and exhibited mild cognitive impairment without seizures. In both families, functional analysis demonstrated segregation of one allele with complete loss‐of‐function, and one allele with altered biophysical properties consistent with partial loss‐of‐function.SignificanceThese studies demonstrate that SCN8A DEE may, in rare cases, result from inheritance of two variants, both of which exhibit reduced channel activity. In these families, heterozygosity for the dominant variants results in less severe disease than biallelic inheritance of two variant alleles. The clinical consequences of variants with partial and complete loss of SCN8A function are variable and likely to be influenced by genetic background.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153117/1/epi16371_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153117/2/epi16371.pd