The ATLAS experiment will replace the existing Inner Detector by an all-silicon detector named the Inner Tracker (ITk) for the High Luminosity LHC upgrades. In the outer region of the ITk is the ...strip detector, which consists of a four layer barrel and six discs to each side of the barrel, with silicon-strip modules as basic units. Each module is composed of a sensor and one or more flex circuits that hold the read-out electronics. In the experiment, the modules are mounted on support structures with integrated power and cooling. The modules are designed with geometries that accommodate the central (barrel) and forward (end-cap) regions, with rectangular sensors in the barrels and wedge shaped sensors in the end-caps. The strips lengths and pitch sizes vary according to the occupancy of the region.
In this contribution, we present the construction and results of the electrical tests of the first full-size module of the innermost forward region, named Ring 0 in the ATLAS ITk strip detector nomenclature. This module uses a sensor with stereo annulus geometry, having four segments of strips of different lengths and pitch. The two innermost strips segments are read out through eight chips, for a total of 2048 strips, while the two outermost segments are read out through nine chips, for a total of 2304 strips. We introduce the assembly procedure that lead to the construction of the module as well as the testing during the intermediate steps.
A novel microstrip sensor geometry, the stereo annulus, has been developed for use in the end-cap of the ATLAS experiment’s strip tracker upgrade at the HL-LHC. Its first implementation is in the ...ATLAS12EC sensors, a large-area, radiation-hard, single-sided, AC-coupled, n+-in-p design produced by the ITk Strip Sensor Collaboration and fabricated by Hamamatsu Photonics in early 2017. The results of the initial testing of two ATLAS12EC batches are presented here with a comparison to specification. The potential of the new sensor shape to reinvigorate endcap strip tracking is explained and its effects on sensor performance are isolated by comparing the bulk mechanical and electrical properties of the new sensor to the previous iteration of prototype, the conventional barrel ATLAS12A sensor. The surface properties of the new sensor are evaluated for full-size unirradiated sensors as well as for mini sensors unirradiated and irradiated with protons up to a fluence of 2.2×1015neq cm−2. The results show that the new stereo annulus ATLAS12EC sensors exhibit excellent performance and the expected irradiation evolution.
The planned High Luminosity Large Hadron Collider is being designed to maximise the physics potential of the LHC with 10 years of operation at instantaneous luminosities of 7.5×1034cm−2s−1. A ...consequence of this increased luminosity is the expected radiation damage requiring the tracking detectors to withstand hadron fluence to over 1×1015 1 MeV neutron equivalent per cm2 in the ATLAS Strips system. Fast readout electronics, deploying 130 nm CMOS front-end electronics are glued on top of a silicon sensor to make a module. The radiation hard n-in-p micro-strip sensors used have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics. A series of tests were performed at the DESY-II test beam facility to investigate the detailed performance of a strip module with both 2.5 cm and 5 cm length strips before irradiation. The DURANTA telescope was used to obtain a pointing resolution of 2 μm, with an additional pixel layer installed to improve timing resolution to ∼25 ns. Results show that prior to irradiation a wide range of thresholds (0.5–2.0 fC) meet the requirements of a noise occupancy less than 1×10−3 and a hit efficiency greater than 99%.
A detailed description of the integration structures for the barrel region of the silicon strips tracker of the ATLAS Phase-II upgrade for the upgrade of the Large Hadron Collider, the so-called High ...Luminosity LHC (HL-LHC), is presented. This paper focuses on one of the latest demonstrator prototypes recently assembled, with numerous unique features. It consists of a shortened, shield-less, and double sided stave, with two candidate power distributions implemented. Thermal and electrical performances of the prototype are presented, as well as a description of the assembly procedures and tools.
In order to cope with the occupancy and radiation doses expected at the High-Luminosity LHC, the ATLAS experiment will replace its Inner Detector with an all-silicon Inner Tracker (ITk), consisting ...of pixel and strip subsystems.
In the last two years, several prototype ITk strip modules have been tested using beams of high energy electrons produced at the DESY-II testbeam facility. Tracking was provided by EUDET telescopes. The modules tested are built from two sensor types: the rectangular ATLAS17LS, which will be used in the outer layers of the central barrel region of the detector, and the annular ATLAS12EC, which will be used in the innermost ring (R0) of the forward region. Additionally, a structure with two R0 modules positioned back-to-back has been measured, demonstrating space point reconstruction using the stereo angle of the strips. Finally, one barrel and one R0 module have been measured after irradiation to 40% beyond the expected end-of-lifetime fluence. The data obtained allow for thorough tests of the module performance, including charge collection, noise occupancy, detection efficiency, and tracking performance. The results give confidence that the ITk strip detector will meet the requirements of the ATLAS experiment.
A novel microstrip sensor geometry, the stereo annulus, has been developed for use in the end-cap of the ATLAS experiment’s strip tracker upgrade at the HL-LHC. Its first implementation is in the ...ATLAS12EC sensors, a large-area, radiation-hard, single-sided, AC-coupled, n+ -in-p design produced by the ITk Strip Sensor Collaboration and fabricated by Hamamatsu Photonics in early 2017. The results of the initial testing of two ATLAS12EC batches are presented here with a comparison to specification. The potential of the new sensor shape to reinvigorate endcap strip tracking is explained and its effects on sensor performance are isolated by comparing the bulk mechanical and electrical properties of the new sensor to the previous iteration of prototype, the conventional barrel ATLAS12A sensor. The surface properties of the new sensor are evaluated for full-size unirradiated sensors as well as for mini sensors unirradiated and irradiated with protons up to a fluence of 2.2 x 1015 neq cm-2. The results show that the new stereo annulus ATLAS12EC sensors exhibit excellent performance and the expected irradiation evolution.
We evaluated the use of laparoscopy in the management of impalpable testis to determine what advantages it might offer over the open approach.
Over a 5.5-year period, a total of 46 patients with 53 ...nonpalpable testes underwent a laparoscopic procedure at our hospital. There were 28 cases of intraabdominal testis (52.83%), 18 cases of the vas and vessels entering the internal ring (33.96%), and seven cases of intraabdominally absent testis (13.20%). We performed a laparoscopic orchiopexy for 24 testes (scrotal in 21 cases and partial to the inguinal canal in three cases) and an orchiectomy for three testes. We encountered inguinal hernia in 14 cases (26.41%).
At follow-up, all testes were the same size as at the time of operation and were well positioned in the scrotum, except for four testes that required reoperation due to partial migration at the superficial inguinal ring. The operating time was <1 h in unilateral cases and <2 h for the bilateral cases. All procedures were completed successfully without conversion or complications.
Laparoscopy is the only exploratory procedure that is accurate enough to enable the diagnosis of nonpalpable testis and also allow the surgical treatment to be done in the same setting.
Carney's triad is extremely rare. The authors report on a 12-year-old patient who had gastric epithelioid leiomyosarcoma, multiple pulmonary chondroma, and mediastinal paraganglioma. Thirty-five ...other cases are reviewed and analyzed.
Abstract only Baseline HCHS/SOL data recently showed that prevalence of obesity varied markedly by sex and Hispanic/Latino background. Despite increasing prevalence of obesity in the US, little data ...exist on incidence of overweight and obesity in diverse US Hispanic/Latino adults. This study examined ~6-year incidence rate of overweight and obesity in this population by demographic factors. Methods: HCHS/SOL is a multi-center prospective community-based study of 16,415 diverse Hispanic/Latino adults in the US, ages 18-74 at Visit 1 (2008-11). Visit 2 (2014-17) is ongoing, with 10,914 persons reexamined by August 2017. Analyses included 10,427 persons with complete data on body mass index (BMI) at both visits and on other variables of interest; underweight persons were excluded. Age-adjusted incidence rate of overweight (BMI 25.0-29.9 kg/m 2 ; among those normal-weight at baseline), and obesity (BMI > 30 kg/m 2 ; in those non-obese at baseline) was computed by sex and Hispanic/Latino background, accounting for the complex study design. Results: In ~6 years, 572 and 765 new cases of overweight and obesity were seen among baseline normal-weight (n=1924) and non-obese (n=5912) participants, respectively. Among men and women, age-adjusted incidence of overweight was 5.45 and 5.33 per 100 person years (PY); age-adjusted obesity incidence was 2.00 and 2.56 /100 PY. Incidence rates varied by background. Among men, overweight incidence was highest in those of Mexican background (6.95 /100 PY), and among women, in those of Puerto Rican background (6.94/ 100 PY). Incidence of obesity was highest in Dominican-background men (2.35/ 100 PY) and Cuban-background women (3.85/ 100 PY) ( Table ). Incidence rates varied slightly by age group, from 4.06 to 5.98/100 PY in those ages 18-44 and 65+ years. Conclusion: Of every 100 US Hispanic/Latino adults about 5 and 2 became overweight and obese each year, augmenting the existing high prevalence. Greater efforts are needed to prevent onset of overweight and obesity in this population from young adulthood onwards.
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