Experimental Tests of Neutron Shielding for the ATLAS Forward Region

Experimental tests devoted to the optimization of the neutron shielding for the ATLAS forward region were performed at the CERN-PS with a 4 GeV/c proton beam. Spectra of fast neutrons, slow neutrons and gamma rays escaping a block of iron (40$\times$40$\times$80 cm$^3$) shielded with different types of neutron and gamma shields (pure polyethylene - PE, borated polyethylene - BPE, lithium filled polyethylene - LiPE, lead, iron) were measured by means of plastic scintillators, a Bonner spectrometer, a HPGe detector and a slow neutron detector. Effectiveness of different types of shielding agaisnt neutrons and $\gamma$-rays were compared. The idea of a segmented outer layer shielding (iron, BPE, iron, LiPE) for the ATLAS Forward Region was also tested

LHC1: a semiconductor pixel detector readout chip with internal, tunable delay providing a binary pattern of selected events

The Omega3/LHCl pixel detector readout chip comprises a matrix of 128 X 16 readout cells of 50 mu m X 500 mu m and peripheral functions with 4 distinct modes of initialization and operation, together more than 800 000 transistors. Each cell contains a complete chain of amplifier, discriminator with adjustable threshold and fast-OR output, a globally adjustable delay with local fine-tuning, coincidence logic and memory. Every cell can be individually addressed for electrical test and masking, First results have been obtained from electrical tests of a chip without detector as well as from source measurements, The electronic noise without detector is similar to 100 e(-) rms. The lowest threshold setting is close to 2000 e(-) and non-uniformity has been measured to be better than 450 e(-) rms at 5000 e(-) threshold. A timewalk of < 10 ns and a precision of < 6 ns rms on a delay of 2 mu s have been measured. The results may be improved by further optimization

The relationship between water, sanitation and schistosomiasis : a systematic review and meta-analysis

BACKGROUND: Access to "safe" water and "adequate" sanitation are emphasized as important measures for schistosomiasis control. Indeed, the schistosomes' lifecycles suggest that their transmission may be reduced through safe water and adequate sanitation. However, the evidence has not previously been compiled in a systematic review. METHODOLOGY: We carried out a systematic review and meta-analysis of studies reporting schistosome infection rates in people who do or do not have access to safe water and adequate sanitation. PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to 31 December 2013, without restrictions on year of publication or language. Studies' titles and abstracts were screened by two independent assessors. Papers deemed of interest were read in full and appropriate studies included in the meta-analysis. Publication bias was assessed through the visual inspection of funnel plots and through Egger's test. Heterogeneity of datasets within the meta-analysis was quantified using Higgins' I2. PRINCIPAL FINDINGS: Safe water supplies were associated with significantly lower odds of schistosomiasis (odds ratio (OR) = 0.53, 95% confidence interval (CI): 0.47-0.61). Adequate sanitation was associated with lower odds of Schistosoma mansoni, (OR = 0.59, 95% CI: 0.47-0.73) and Schistosoma haematobium (OR = 0.69, 95% CI: 0.57-0.84). Included studies were mainly cross-sectional and quality was largely poor. CONCLUSIONS/SIGNIFICANCE: Our systematic review and meta-analysis suggests that increasing access to safe water and adequate sanitation are important measures to reduce the odds of schistosome infection. However, most of the studies were observational and quality was poor. Hence, there is a pressing need for adequately powered cluster randomized trials comparing schistosome infection risk with access to safe water and adequate sanitation, more studies which rigorously define water and sanitation, and new research on the relationships between water, sanitation, hygiene, human behavior, and schistosome transmissio

Space resolution of a silicon pixel detector as a function of the track angle

We measured the spatial resolution of a 300 \u3bcm thick 75 7 500 \u3bcm silicon pixel detector as a function of the track angle using a 120 GeV pion beam. We observed that 13% of tracks perpendicular to the detector give a signal on two neighboring pixels; this fraction increases to 50% at an angle of 15\ub0 w.r.t. the normal incidence direction. The average spatial resolution is 28.2 \u3bcm at 0\ub0 and 14.6 \u3bcm at 15\ub0. The detector efficiency is not affected by the charge sharing between pixels. Our data agree with the predictions of a simple geometrical model describing the charge sharing in the region between pixels. This model can be the basis for a full simulation of the behaviour of a pixel detector

Uniformity of response of the LHC1 large area pixel detector system

The uniformity of discriminator threshold and the precision of internal delay have been studied on single 'Omega3/LHC1' pixel readout chips and on arrays of 24 chips containing 48 768 active pixels. On single chips we measured a threshold variation of 400e(-) r.m.s, for a mean threshold setting of 4000e(-). The internal delay distribution shows a standard deviation of 6 ns on a single chip and 16 ns on the large arrays, after applying a 3-bit delay adjustment. These results, obtained using an electrical stimulus, were confirmed by tests in a beam of high-energy particles. (C) 1998 Elsevier Science B.V. All rights reserved

Studies on a 300 k pixel detector telescope

Four silicon pixel detector planes are combined to form a tracking telescope in the lead ion experiment WA97 at CERN with 290 304 sensitive elements each of 75 mu m by 500 mu m area. An electronic pulse processing circuit is associated with each individual sensing element and the response for ionizing particles is binary with an adjustable threshold. The noise rate for a threshold of 6000 e(-) has been measured to be less than 10-(10). The inefficient area due to malfunctioning pixels is 2.8% of the 120 cm(2). Detector overlaps within one plane have been used to determine the alignment of the components of the plane itself, without need for track reconstruction using external detectors. It is the first time that such a big surface covered with active pixels has been used in a physics experiment. Some aspects concerning inclined particle tracks and time walk have been measured separately in a beam test at the CERN SPS H6 beam