Abstract
The Deep Underground Neutrino Experiment (DUNE) is a next
generation experiment aimed to study neutrino oscillation. Its
long-baseline configuration will exploit a Near Detector (ND) and a
...Far Detector (FD) located at a distance of ∼1300 km. The FD
will consist of four Liquid Argon Time Projection Chamber (LAr TPC)
modules. A Photon Detection System (PDS) will be used to detect the
scintillation light produced inside the detector after neutrino
interactions. The PDS will be based on light collectors coupled to
Silicon Photomultipliers (SiPMs). Different photosensor
technologies have been proposed and produced in order to identify
the best samples to fullfill the experiment requirements. In this
paper, we present the procedure and results of a validation campaign
for the Hole Wire Bonding (HWB) MPPCs samples produced by Hamamatsu
Photonics K.K. (HPK) for the DUNE experiment, referring to them as
`SiPMs'. The protocol for a characterization at cryogenic
temperature (77 K) is reported. We present the down-selection
criteria and the results obtained during the selection campaign
undertaken, along with a study of the main sources of noise of the
SiPMs including the investigation of a newly observed phenomenon in
this field.
Abstract
The Muon
g
-2 Experiment at Fermilab uses a gaseous straw
tracking detector to make detailed measurements of the stored muon
beam profile, which are essential for the experiment to achieve ...its
uncertainty goals. Positrons from muon decays spiral inward and pass
through the tracking detector before striking an electromagnetic
calorimeter. The tracking detector is therefore located inside the
vacuum chamber in a region where the magnetic field is large and
non-uniform. As such, the tracking detector must have a low leak
rate to maintain a high-quality vacuum, must be non-magnetic so as
not to perturb the magnetic field and, to minimize energy loss, must
have a low radiation length. The performance of the tracking
detector has met or surpassed the design requirements, with adequate
electronic noise levels, an average straw hit resolution of
(110 ± 20) μm, a detection efficiency of 97% or higher,
and no performance degradation or signs of aging. The tracking
detector's measurements result in an otherwise unachievable
understanding of the muon's beam motion, particularly at early times
in the experiment's measurement period when there are a
significantly greater number of muons decaying. This is vital to the
statistical power of the experiment, as well as facilitating the
precise extraction of several systematic corrections and
uncertainties. This paper describes the design, construction,
testing, commissioning, and performance of the tracking detector.
The Muon g − 2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency ωam to an uncertainty of 434 parts per billion (ppb), statistical, and ...56 ppb, systematic, with data collected in four storage ring configurations during its first physics run in 2018. When combined with a precision measurement of the magnetic field of the experiment's muon storage ring, the precession frequency measurement determines a muon magnetic anomaly of aμ ( FNAL ) = 116 592 040 ( 54 ) × 10−11 (0.46 ppm). This article describes the multiple techniques employed in the reconstruction, analysis, and fitting of the data to measure the precession frequency. It also presents the averaging of the results from the 11 separate determinations of ωam, and the systematic uncertainties on the result.
We present a new measurement of the positive muon magnetic anomaly, $a$$μ$≡($g$$μ$-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 ...times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution $\tilde {ω}$'p, and of the anomalous precession frequency corrected for beam dynamics effects, $ω$$a$. From the ratio $ω$$a$/$\tilde {ω}$'$p$, together with precisely determined external parameters, we determine $a$$μ$ = 116592057(25)×10-11 (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain aμ(FNAL)=116592055(24)×10-11 (0.20 ppm). The new experimental world average is $a$$μ$(Exp)=116592059(22)×10-11 (0.19 ppm), which represents a factor of 2 improvement in precision.
Large-scale medical sequencing provides a focal point around which to reorganize health care and health care research. Mobile health (mHealth) is also currently undergoing explosive growth and could ...be another innovation that will change the face of future health care. We are employing primary ovarian insufficiency (POI) as a model rare condition to explore the intersection of these potentials. As both sequencing capabilities and our ability to intepret this information improve, sequencing for medical purposes will play an increasing role in health care beyond basic research: it will help guide the delivery of care to patients. POI is a serious chronic disorder and syndrome characterized by hypergonadotrophic hypogonadism before the age of 40 years and most commonly presents with amenorrhea. It may have adverse health effects that become fully evident years after the initial diagnosis. The condition is most commonly viewed as one of infertility, however, it may also be associated with adverse long-term outcomes related to inadequate bone mineral density, increased risk of cardiovascular disease, adrenal insufficiency, hypothyroidism and, if pregnancy ensues, having a child with Fragile X Syndrome. There may also be adverse outcomes related to increased rates of anxiety and depression. POI is also a rare disease, and accordingly, presents special challenges. Too often advances in research are not effectively integrated into community care at the point of service for those with rare diseases. There is a need to connect community health providers in real time with investigators who have the requisite knowledge and expertise to help manage the rare disease and to conduct ongoing research. Here we review the pathophysiology and management of POI and propose the development of an international Clinical Research Integration Special Program (CRISP) for the condition.
Histoplasmosis is a serious opportunistic infection in patients with AIDS, often representing the first manifestation of the syndrome. Most infections occurring within the endemic region are caused ...by exogenous exposure, while those occurring in nonendemic areas may represent endogenous reactivation of latent foci of infection or exogenous exposure to microfoci located within those nonendemic regions. However, prospective investigations are needed to prove the mode of acquisition. The infection usually begins in the lungs even though the chest roentgenogram may be normal. Clinical findings are nonspecific; most patients present with symptoms of fever and weight loss of at least 1 month's duration. When untreated, many cases eventually develop severe clinical manifestations resembling septicemia. Chest roentgenograms, when abnormal, show interstitial or reticulonodular infiltrates. Many cases have been initially misdiagnosed as disseminated mycobacterial infection or Pneumocystis carinii pneumonia. Patients are often concurrently infected with other opportunistic pathogens, supporting the need for a careful search for co-infections. Useful diagnostic tests include serologic tests for anti-H. capsulatum antibodies and HPA, silver stains of tissue sections or body fluids, and cultures using fungal media from blood, bone marrow, bronchoalveolar lavage fluid, and other tissues or body fluids suspected to be infected on clinical grounds. Treatment with amphotericin B is highly effective, reversing the clinical manifestations of infection in at least 80% of cases. However, nearly all patients relapse within 1 year after completing courses of amphotericin B of 35 mg/kg or more, supporting the use of maintenance treatment to prevent recurrence. Relapse rates are lower (9 to 19%) in patients receiving maintenance therapy with amphotericin B given at doses of about 50 mg weekly or biweekly than with ketoconazole (50-60%), but controlled trials comparing different maintenance regimens have not been conducted. Until results of such trials become available, our current approach is to administer an induction phase of 15 mg/kg of amphotericin B given over 4 to 6 weeks, followed by maintenance therapy with 50 to 100 mg of amphotericin B given once or twice weekly, or biweekly. If results of a prospective National Institutes of Allergy and Infectious Disease study of itraconazole maintenance therapy document its effectiveness, alternatives to amphotericin B may be reasonable.
A driving force for moisture migration, namely, a gradient in water chemical potential from the shell to the center in freshly panned jellybeans, was revealed by water activity measurements. ...Subsequent three-dimensional imaging by a nuclear magnetic resonance technique (single point ramped imaging
T
1 enhanced, SPRITE), especially suited for detection of components with restricted mobility as in low moisture foods, demonstrated the migration of moisture from the shell to and through the center over a 48 h period following engrossing. During this period, nuclear relaxation times were longer in the shell than in the center, where strong magnetic interactions with macromolecules are probably enhanced by proton exchange and hydrogen bonding. While some mass transfer occurs between the shell and the center, measurements of total NMR image intensity suggest a net loss of moisture from the jellybean to the atmosphere. This was verified by gravimetric measurements, which also indicated that the process is diffusion-limited. It appears that attempts to reduce the aging period between engrossing and polishing of jellybeans should be geared toward factors that increase the diffusion of moisture.
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