Jay W. Dawson

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This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events(More)
Ultrafast dynamics in a 1Spm tensile-strained quantum-well optical amplifier has been studied by highly nondegenerate four-wave mixing at detuning frequencies up to 1.7 THz. Frequency response data indicate the presence of two ultrafast physical processes with characteristic relaxation lifetimes of 650 fs and < 100 fs. The longer time constant is believed(More)
An all fiber, widely tunable, single-frequency, erbium-doped fiber ring laser was constructed with a threshold pump power as low as 10 mW. Tuning over more than 30 nm was obtained by applying 0 to 17 dc V to an intracavity fiber Fabry-Perot filter. Threshold pump power versus wavelength data showed low variation over the tuning range. Mode hopping(More)
We demonstrate a delayed self-heterodyne interfer-ometer with a recirculating delay, in which loss is partially compensated by an erbium-doped fiber amplifier. A resolution limit ofr606 Hz is achieved with an 11 km fiber delay line, as compared to 18.2 kHz for the standard single-pass case. The possible effect of spectral broadening due to amplifier noise(More)
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 and charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward-to downward-going events in(More)
After the rst positive results of 1993, the RD34 collaboration pursued additional R&D on the eld of sampling hadron calorimetry. The proposed calorimeter, adopted by the ATLAS experiment, uses steel as absorber and scintillating tiles placed in planes perpendicular to the colliding beams. Its mechanical design, component tests, scintillator properties and(More)
An all-fiber, single-frequency, erbium-doped ring laser has been frequency locked to a resonance peak of an external fiber Fabry-Perot resonator by the Pound-Drever technique. In addition, feedback to the mode selection filter in the laser resonator eliminates occasional mode hopping completely, resulting in frequency-locked, stable, single-frequency(More)
The high frequency intensity noise of a tandem fiber Fabry-Perot erbium-doped fiber ring laser is reduced to the standard quantum limit, with a 0.5 dB experimental uncertainty. Noise reduction of > 14 dB is achieved by intracavity spectral filtering of weak side modes using a narrow-band fiber Fabry-Perot etalon. Broadly tunable, single-frequency(More)
The intensity noise of an erbium-doped fiber ring laser is measured relative to the standard quantum limit. Over a tuning range of 24 nm, the noise power is within 20 dB of the shot noise floor and varies linearly with laser output power. Oscillations in the noise power spectrum are observed and attributed to beating of the lasing mode with other, strongly(More)