[en] Measurements of radial fingering patterns have been performed over a range of dimensionless force parameter 1.1≤C≤35. All observed flows show a power law dependence of radius of gyration on area with exponent (1/1.79). Local curvatures provide the best characterization of pattern ramification. The power spectra of these curvatures are used to define an average wave number K-bar. A scaling is observed to collapse dimensionless average wave number (K-bar') versus dimensionless area of the mixing zone onto one function which rises early in the flows and then coarsens as the flows become more developed

[en] The two most recent and precise measurements of the charged kaon mass use X-rays from kaonic atoms and report uncertainties of 14 ppm and 22 ppm yet differ from each other by 122 ppm. We describe the possibility of an independent mass measurement using the measurement of Cherenkov light from a narrow-band beam of kaons, pions, and protons. This technique was demonstrated using data taken opportunistically by the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory which recorded beams of protons, kaons, and pions ranging in momentum from +37 GeV/c to +63 GeV/c. The measured value is 491.3 ± 1.7 MeV/c², which is within 1.4σ of the world average. An improvement of two orders of magnitude in precision would make this technique useful for resolving the ambiguity in the X-ray data and may be achievable in a dedicated experiment

[en] The rate of high energy cosmic ray muons as measured underground is shown to be strongly correlated with upper-air temperatures during short-term atmospheric (10-day) events. The effects are seen by correlating data from the MINOS underground detector and temperatures from the European Centre for Medium Range Weather Forecasts during the winter periods from 2003-2007. This effect provides an independent technique for the measurement of meteorological conditions and presents a unique opportunity to measure both short and long-term changes in this important part of the atmosphere

[en] In this paper, the authors present new results from a cryogenic detector instrumented to measure both the phonon and ionization signals. The detector is a 60 g Ge disk operated at 30 mK. The authors have made significant improvements in the electronics noise, threshold, and energy resolution of the device. The baseline FWHM, corresponding to the total system noise, is 1.55 keV in the phonon channel and 1.59 keV in the ionization channel. At 60 keV the FWHM are 1.9 keV and 1.7 keV in the phonon and ionization channels, respectively. The authors have demonstrated for the first time a discrimination between electron recoils and nuclear recoils at low energy

[en] The Department of Energy has initiated its Stockpile Stewardship and Management Program (SSMP) to provide a single, integrated technical program for maintaining the continued safety and reliability of the nation's nuclear weapons stockpile in the absence of nuclear testing. Consistent with the SSMP, the Advanced Hydrotest Facility (AHF) has been conceived to provide improved radiographic imaging with multiple axes and multiple time frames. The AHF would be used to better understand the evolution of nuclear weapon primary implosion shape under normal and accident scenarios. There are three fundamental technologies currently under consideration for use on the AHF. These include linear induction acceleration, inductive-adder pulsed-power technology (both technologies using high current electron beams to produce an intense X-ray beam) and high-energy proton accelerators to produce a proton beam. The Scrounge-atron (a proton synchrotron) was conceived to be a relatively low cost demonstration of the viability of the third technology using bursts of energetic protons, magnetic lenses, and particle detectors to produce the radiographic image. In order for the Scrounge-atron to provide information useful for the AHF technology decision, the accelerator would have to be built as quickly and as economically as possible. These conditions can be met by scrounging parts from decommissioned accelerators across the country, especially the Main Ring at Fermilab. The Scrounge-atron is designed to meet the baseline parameters for single axis proton radiography: a 20 GeV proton beam of ten pulses, 10¹¹ protons each, spaced 250 ns apart

[en] The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of ν_μ and (bar ν)_μ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations giving: R_up/down^data/R_up/down^MC = 0.62_-0.14^+0.19(stat.) ± 0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3T MINOS magnetic field ν_μ and (bar ν)_μ interactions are separated. The ratio of (bar ν)_μ to ν_μ events in the data is compared to the Monte Carlo expectation assuming neutrinos and anti-neutrinos oscillate in same manner giving: R_#bar _ν)#sub _μ)/ν#sub _μ)^data/R_#bar _ν)#sub _μ)/ν#sub _μ)^MC = 0.96_-0.27^+0.38(stat.) ± 0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for ν_μ and (bar ν)_μ

[en] We discuss the status of a cryogenic dark matter search beginning operation in the Stanford Underground Facility. The detectors will be cooled in a specially designed cryostat connected to a modified side access Oxford 400 dilution refrigerator. We discuss two detector designs and performance, the cryostat construction and operation, and the multi-level shield surrounding the cryostat. Finally, we will examine the limits which we will be able to set on WIMP dark matter with this experiment. (orig.)

[en] We report on the latest results from the CDMS (cryogenic dark matter search) experiment. The experiment uses superconducting particle detectors, operated below 100 mK, to search for dark matter in the form of weakly interacting massive elementary particles or WIMPs. These detectors are either Si or Ge crystals, where the electron-hole production and the phonon production are measured for each event, allowing the discrimination of electron recoils (most backgrounds due to gammas and betas) from nuclear recoils (due to WIMPs and neutrons). We have recently reported new limits from the Stanford shallow site experiment (CDMS-I) which explore supersymmetric models where the lightest supersymmetric particle is often an excellent WIMP candidate. We will also report on the Soudan deep site facility for the CDMS-II experiment which is under construction, and on the status of the CDMS-II detector fabrication

[en] We have constructed a scintillation detector using LiF(W) and studied its response to neutron and gamma sources. We could not detect any signals from low energy photons because its scintillation efficiency is only 6-7% of the efficiency of NaI(Tl). We did observe the Compton edges due to ¹³⁷Cs and ⁴⁰K sources. We also observed thermal neutrons by the reaction ⁶Li(n,α³)H. The thermal neutron peak had a resolution (FWHM) of ∼17%. Finally, we observed events due to the cosmic ray muon flux in our laboratory. (orig.)

[en] We report on the performance of a 60 g Ge detector that measures both ionization and phonons at cryogenic (∝25 mK) temperatures. This simultaneous measurements is a powerful new tool in experiments where the primary signal is a nuclear recoil (e.g., WIMP dark matter) that must be distinguished from a background of photons or charged particles that produce electron recoils. We have measured nuclear recoils produced by neutrons from a ²⁵²Cf source, and can distinguish them from photons at energies as low as 2 keV in the ionization measurement. An important effect that can limit the efficiency of the background rejection technique is incomplete charge collection. We have tested our detector at ionization drift fields as low as 5 mV/cm and find that the phonon energy measured for each event depends on the amount of charge collected. From this we deduce details about charge trapping mechanisms. (orig.)