Demonstration of a lightguide detector for liquid argon TPCs Bugel, L.; Conrad, J.M.; Ignarra, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2011, Letnik:
640, Številka:
1
Journal Article
Recenzirano
We report demonstration of light detection in liquid argon using an acrylic lightguide detector system. This opens the opportunity for development of an inexpensive, large-area light collection ...system for large liquid argon time projection chambers. The guides are constructed of acrylic with TPB embedded in a surface coating with a matching index of refraction. We study the response to early scintillation light produced by a 5.3
MeV
α
. We measure coating responses from 7 to 8 PE on average, compared to an ideal expectation of 10 PE on average. We estimate the attenuation length of light along the lightguide bar to be greater than 0.5
m. The coating response and the attenuation length can be improved. As a benchmark of the present capability, we show a 30 paddle design meets the requirement of the MicroBooNE Experiment, which is efficient triggering on 40
MeV protons produced by neutrino neutral current elastic scatters.
The MicroBooNE detector, to be located on axis in the Booster Neutrino Beamline (BNB) at the Fermi National Accelerator Laboratory (Fermilab), consists of two main components: a large liquid argon ...time projection chamber (LArTPC), and a light collection system. Thirty-two 8-inch diameter Hamamatsu R5912-02mod cryogenic photomultiplier tubes (PMTs) will detect the scintillation light generated in the liquid argon (LAr). This article first describes the MicroBooNE PMT performance test procedures, including how the light collection system functions in the detector, and the design of the PMT base. The design of the cryogenic test stand is then discussed, and finally the results of the cryogenic tests are reported.
(1) Relationships between vegetation composition and nutrient and major ion concentrations in groundwater and peat were examined in 58 stands of fen vegetation in the Biebrza mire, Poland. The 58 ...stands included rich fens with a large standing biomass, rich fens with lower standing biomass and poor fens. (2) The highly productive rich fen (i.e. rich fen with large standing biomass) receives moderately eutrophic river water. The rheophilous part of the mire that is not, or only occasionally flooded contains gradients from quite productive rich fens to less productive rich fens and poor fens. In this part of the gradient, occasional river flooding appeared to be an important source of K and was probably responsible for the presence of quite productive rich fen vegetation. (3) Upward seepage of calcium-rich and phosphate-poor groundwater keeps phosphate concentration low in the superficial mire water and the peat from the lower productive rich fen. Phosphate concentration is higher in the mire water and the peat from the poor fen which is fed by downward-flowing rainwater. (4) Nitrogen concentration in mire water and peat is only poorly correlated with species composition and vegetation structure.
Despite substantial activity surrounding the municipalization of electric utilities as a means of obtaining lower electricity prices, when the New Mexico Supreme Court first confronted a case of the ...municipalization of a private utility by condemnation it dealt with a water and sewage utility. The court concluded that the New Mexico Public Utility Commission had no jurisdiction over Rio Rancho's condemnation of its local water utility. That decision, though good for water utilities, which often serve as a means for communities to control growth, may have detrimental effects on some of New Mexico's electricity consumers. Unlike water utilities, electric utilities are usually large and interconnected to numerous other communities. When one community leaves a system, the remaining communities will likely pay both financially and in terms of a decrease in service quality. Without oversight from the Public Utility Commission, those effects are not taken into consideration and balanced with other concerns when deciding when and how a community can leave a system. Las Cruces' municipalization of El Paso Electric's systems within its borders could require the remaining customers to pay higher rates, a concern that should be addressed by the Commission.
Purpose To investigate the efficacy and safety of zoledronic acid (ZA) combined with targeted therapy (TT). Materials and Methods A retrospective study was performed in patients with metastatic renal ...cell carcinoma treated with ZA and TT. Results Twenty-one patients received ZA and TT to prevent skeletal-related events and no pretherapy oral and maxillofacial (OM) examination (cohort A). Six patients (29%) developed osteonecrosis of the jaw (ONJ), which was observed only in patients receiving sunitinib and ZA. Sixteen patients received TT and ZA for hypercalcemia and no pretherapy OM examination (cohort B). In these patients, no ONJ was observed. Nine patients received ZA and TT and pretherapy OM examination (cohort C). One patient (11%) developed ONJ during sunitinib and ZA treatment. Mean skeletal morbidity rates were 0.8 for cohort A and 1.2 for cohort C. In the combined cohort (A plus C; n = 30), 47% developed skeletal-related events, 7% pathologic fracture, 7% medullary compression, and 37% progression of bone metastases. Patients who developed ONJ had a significantly improved median survival of 31.6 months compared with 14.5 months in patients without ONJ ( P = .039). Conclusion The combination of ZA and TT resulted in high, clinically meaningful activity. ONJ may be exacerbated by concomitant ZA and sunitinib. Regular OM examinations before and during treatment are recommended.
Hypertrophic cardiomyopathy is the most common monogenic cardiovascular disease that is caused by sarcomeric protein gene mutations. A hallmark of the most common form of the disease is outflow ...obstruction secondary to systolic narrowing of the left ventricular outflow tract from septal hypertrophy, mitral valve abnormalities and, most importantly, hyperdynamic contractility. Recent mechanistic studies have identified excessive myosin adenosine triphosphatase activation and actin-myosin cross-bridging as major underlying causes. These studies have led to the development of mavacamten, a first-in-class myosin adenosine triphosphatase inhibitor and the first specific therapy for hypertrophic obstructive cardiomyopathy. Preclinical and subsequent pivotal clinical studies have demonstrated the efficacy and safety of mavacamten. A remarkable improvement among treated patients in peak oxygen consumption, functional capacity, symptom relief and post-exercise left ventricular outflow tract gradient, along with dramatic reductions in heart failure biomarkers, suggests that this new medication will be transformative for the symptom management of hypertrophic obstructive cardiomyopathy. There is also hope and early evidence that mavacamten may delay or obviate the need for invasive septal reduction therapies. In this article, we review the current evidence for the efficacy and safety of mavacamten and highlight important considerations for its clinical use.
(1) A computer model was used to simulate changes in heathland composition after fire. The model is based on simple stochastic representations of establishment, growth, mortality and competition for ...space. (2) Model parameters--establishment rates, maximum diameters and heights and growth constants--were estimated for Calluna vulgaris, Empetrum nigrum and Erica tetralix on a heathland in the Netherlands where these three species are co-dominant. (3) The resulting simulations were compared with cover data for 19 years from a mapped 12 m × 20 m permanent quadrat. Apart from the temporary effects of a drought, the cover percentages lay almost entirely within a 90% probability envelope obtained from the replicate simulations. Trends with time in transition frequencies among species were also correctly predicted. (4) Factorial sensitivity experiments simulated responses of the mature community to changes in the growth constants and establishment rates of these species. These experiments also revealed differences in the strategies of the species, compensatory and synergistic effects, and an instance of competitive mutualism--illustrating the complex community behaviour that can emerge from a relatively simple model. (5) The mature community is not at an uneven-aged equilibrium and, in the long-term, natural disturbances, climatic variation and rational management may prevent this.
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