[en] In contrast to the predictions of the Standard Model of particle physics, experimental data now indicate that neutrinos are massive and undergo flavor oscillations. Indeed, observations of atmospheric neutrinos have confirmed that the disappearance of high-energy muon-like events is well described by the conversion of ν_μ into ν_τ. Though the primary atmospheric neutrino flux at these energies is composed almost exclusively of ν_e and ν_μ, this transition implies that it is also possible to observe ν_τ-induced events. Recent results from the Super-Kamiokande ν_μ disappearance analysis as well the search for the subsequent appearance of ν_τ events in the data are presented.

[en] We present a block design that facilitates split-field tests, a technique frequently employed to assess several potential misalignments in linear accelerators. Two tests are possible with this device using: (1) opposed collimator angles and (2) opposed gantry angles. The first test is sensitive to jaw symmetry only. In the second test, the alignment of one field edge indicates gantry sag, while the other field edge is sensitive to the combined effects of jaw asymmetry, misalignment of the beam spot, and misalignment of the gantry and collimator rotation axes. The block arrangement consists of a pattern of three polygons cast in lead or Cerrobend. The assembly mounts in the accessory tray of the accelerator and allows all necessary exposures to be taken in a single room entry. Any field size up to 24 cm can be tested with the assembly constructed here. A simultaneous test of light field-radiation field coincidence can also be accommodated. Exposed films with a prototype device show that offsets of ±1 mm are readily visible. The block design facilitates the required measurements for split-field tests and makes this a practical technique for routine quality assurance on a linear accelerator

[en] This Direct Feed Low-Activity Waste (DFLAW) Program paper describes the key programmatic elements to enable the startup of treatment and disposal of Hanford tank waste through a phased startup of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Specifically the DFLAW Program consists of the Low- Activity Waste (LAW) vitrification facility, and the direct feed to LAW of treated tank farm supernatant from the Low-Activity Waste Pretreatment System (LAWPS). This document identifies the overall strategy, objectives, and processes of the U.S. Department of Energy (DOE), Office of River Protection (ORP) and all supporting DOE subcontractors, and describes the scope of the program elements. In addition gaps, risks, and opportunities to successful integration for commissioning of all needed systems and facilities to produce immobilized LAW product (ILAW) are described. The scope of the DFLAW Program extends up to the point that LAW Facility hot commissioning is complete and all DFLAW systems are fully operational. The DFLAW Program coordinates, integrates, and monitors all the activities necessary to successfully commission and start up the WTP LAW facility. This involves integrating the readiness of all the plant, personnel and program/procedures that support startup of hot commissioning of tank farms systems, WTP systems, waste treatment and disposal systems, and site utility, infrastructure and services. Multiple Hanford contractors have responsibilities to execute and perform scope under the umbrella of the DFLAW Program. The primary focus of the One System organization, comprised of WTP Project and Tank Operations Contract (TOC) personnel, is to manage the coordination and integration across the interfaces of the work scope described above. (authors)

[en] Purpose: Delivering high dose to prostate with external beam radiation has been shown to improve local tumor control. However, it has to be carefully performed to avoid partial target miss and delivering excessive dose to surrounding normal tissues. One way to achieve safe dose escalation is to precisely localize prostate immediately before daily treatment. Therefore, the radiation can be accurately delivered to the target. Once the prostate position is determined with high confidence, planning target volume (PTV) safety margin might be reduced for further reduction of rectal toxicity. A rapid computed tomography (CT)-based online prostate localization method is presented for this purpose. Methods and Materials: Immediately before each treatment session, the patient is immobilized and undergoes a CT scan in the treatment position using a CT scanner situated in the treatment room. At the CT console, posterior, anterior, left, and right extents of the prostate are manually identified on each axial slice. The translational prostate displacements relative to the planned position are estimated by simultaneously fitting these identified extents from this CT scan to a template created from the finely sliced planning CT scan. A total of 106 serial CT scans from 8 prostate cancer patients were performed immediately before treatments and used to retrospectively evaluate the precision of this daily prostate targeting method. The three-dimensional displacement of the prostate with respect to its planned position was estimated. Results: Five axial slices from each treatment CT scan were sufficient to produce a reliable correction when compared with prostate center of gravity (CoG) displacements calculated from physician-drawn contours. The differences (mean ± SD) between these two correction schemes in the right-left (R/L), posterior-anterior (P/A), and superior-inferior (S/I) directions are 0.0 ± 0.4 mm, 0.0 ± 0.7 mm, and -0.4 ± 1.9 mm, respectively. With daily CT extent-fitting correction, 97% of the scans showed that the entire posterior prostate gland was covered by PTV given a margin of 6 mm at the rectum-prostate interface and 10 mm elsewhere. In comparison, only 74% and 65% could be achieved by the corrections based on daily and weekly bony matching on portal images, respectively. Conclusions: Results show that daily CT extent fitting provides a precise correction of prostate position in terms of CoG. Identifying prostate extents on five axial CT slices at the CT console is less time-consuming compared with daily contouring of the prostate on many slices. Taking advantage of the prostate curvature in the longitudinal direction, this method also eliminates the necessity of identifying prostate base and apex. Therefore, it is clinically feasible and should provide an accelerated localization of the prostate immediately before daily treatment

[en] Purpose: To design and implement a noninvasive stereotactic immobilization technique with daily CT image-guided positioning to treat patients with paraspinal lesions accurately and to quantify the systematic and random patient setup errors occurring with this method. Methods and Materials: A stereotactic body frame (SBF) was developed for 'rigid' immobilization of paraspinal patients. The inherent accuracy of this system for stereotactic CT-guided treatment was evaluated with phantom studies. Seven patients with thoracic and lumbar spine lesions were immobilized with the SBF and positioned for 33 treatment fractions using daily CT scans. For all 7 patients, the daily setup errors, as assessed from the daily CT scans, were corrected at each treatment fraction. A retrospective analysis was also performed to assess what the impact on patient treatment would have been without the CT-based corrections (i.e., if patient setup had been performed only with the SBF). Results: The average magnitude of systematic and random errors from uncorrected patient setups using the SBF was approximately 2 mm and 1.5 mm (1 SD), respectively. For fixed phantom targets, the system accuracy for the SBF localization and treatment was shown to be within 1 mm (1 SD) in any direction. Dose-volume histograms incorporating these uncertainties for an intensity-modulated radiotherapy plan for lumbar spine lesions were generated, and the effects on the dose-volume histograms were studied. Conclusion: We demonstrated a very accurate and precise method of patient immobilization and treatment delivery based on a noninvasive SBF and daily image guidance for paraspinal lesions. The SBF provides excellent immobilization for paraspinal targets, with setup accuracy better than 2 mm (1 SD). However, for highly conformal paraspinal treatments, uncorrected systematic and random errors of 2 mm in magnitude can result in a significantly greater (>100%) dose to the spinal cord than planned, even though the planned target coverage may not change substantially. With daily CT guidance using the SBF, we showed that the maximal spinal cord dose is ensured to be within 10-15% of the planned value

[en] A core-collapse supernova will emit a neutrino burst that can be detected on Earth. If the neutrinos travel through the Earth before reaching the detector they oscillate via interaction with Earth's matter, yielding oscillations in the neutrino energy spectrum. The frequency of these oscillations in energy is correlated with the pathlength traveled in the Earth and therefore contains information on the supernova location. For this technique to be useful for pointing, good energy resolution, well-known oscillation parameters and high statistics are required. This method is inferior to pointing with elastic scattering in a water Cherenkov detector but could be applied for scintillator-type detectors which have better energy resolution but weak intrinsic pointing capabilities. By the time a nearby supernova happens the requirements might well be fulfilled, and if no water Cherenkov detector is running at that time it may provide the only possibility to gain directional information. The pointing quality can be further improved by the combination of measurements from multiple detectors and also by taking relative timing into account.

[en] We present a search for nonzero θ₁₃ and deviations of sin²θ₂₃ from 0.5 in the oscillations of atmospheric neutrino data from Super-Kamiokande I, II, and III. No distortions of the neutrino flux consistent with nonzero θ₁₃ are found and both neutrino mass hierarchy hypotheses are in agreement with the data. The data are best fit at Δm²=2.1x10^-3 eV², sin²θ₁₃=0.0, and sin²θ₂₃=0.5. In the normal (inverted) hierarchy θ₁₃ and Δm² are constrained at the one-dimensional 90% C.L. to sin²θ₁₃<0.04(0.09) and 1.9(1.7)x10^-3<Δm²<2.6(2.7)x10^-3 eV². The atmospheric mixing angle is within 0.407≤sin²θ₂₃≤0.583 at 90% C.L.

[en] We report the development of a proton identification method for the Super-Kamiokande (SK) detector. This new tool is applied to the search for events with a single proton track, a high purity neutral current sample of interest for sterile neutrino searches. After selection using a neural network, we observe 38 events in the combined SK-I and SK-II data corresponding to 22 85.1 days of exposure, with an estimated signal-to-background ratio of 1.6 to 1. Proton identification was also applied to a direct search for charged-current quasielastic (CCQE) events, obtaining a high precision sample of fully kinematically reconstructed atmospheric neutrinos, which has not been previously reported in water Cherenkov detectors. The CCQE fraction of this sample is 55%, and its neutrino (as opposed to antineutrino) fraction is 91.7±3%. We selected 78μ-like and 47 e-like events in the SK-I and SK-II data set. With this data, a clear zenith angle distortion of the neutrino direction itself is reported in a sub-GeV sample of μ neutrinos where the lepton angular correlation to the incoming neutrino is weak. Our fit to ν_μ→ν_τ oscillations using the neutrino (L/E) distribution of the CCQE sample alone yields a wide acceptance region compatible with our previous results and excludes the no-oscillation hypothesis at 3-sigma.

[en] The Illinois River was substantially altered during the 20th century with the installation of navigational locks and dams, construction of extensive levee networks, and degradation of water quality. Freshwater mussels were affected by these changes. We used sclerochronology and stable isotopes to evaluate changes over time in age-and-growth and food sources for two mussel species: Amblema plicata and Quadrula quadrula. Specimens were collected in years 1894, 1897, 1909, 1912, 1966, and 2013, and archeological specimens were collected circa 850. The von Bertalanffy growth parameter (K) was similar between 850 and 1897, but it increased by 1912 and remained elevated through 2013. Predicted maximum size (L_inf) increased over the past millennium, and 2013 individuals were over 50% larger than in 850. Growth indices showed similar patterns of continual increases in growth. Shells were enriched in ¹³C and ¹⁵N during the 20th century, but exhibited a partial return to historical conditions by 2013. These patterns are likely attributable to impoundment, nutrient pollution and eutrophication beginning in the early 20th century followed by recent water quality improvement. - Highlights: • Examined changes in mussel growth and shell isotopes after long-term human impacts • Mussel growth and size increased over the past 1000 years, mainly after 1900. • δ¹³C (periostracum) increased after 1900, but returned to historical levels after 1960s. • δ¹⁵N (periostracum) increased after 1900 and remains elevated relative to historical levels. • Shell growth and isotopic signatures track eutrophication and other human impacts

[en] We present an improved measurement of the oscillation between the first two neutrino families based on a 766.3 ton-year exposure of KamLAND to reactor anti-neutrinos. KamLAND observes 258 events with nue-bar energies above 3.4MeV compared to 365.2 events expected in the absence of neutrino oscillation. The confidence level for reactor nue-bar disappearance is now 99.995%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at the 99.9% confidence level but agrees with the distortion expected from nue-bar oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives a best-fit point at ΔMSq=8.3 x 10^-5eV² and tan²θ=0.41. A global analysis of data from KamLAND and solar neutrino experiments yields ΔMSq=8.2^+0.6_-0.5 x 10^-5eV² and tan²θ =0.40^+0.09_-0_.07, the most precise determination to date