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Selected Works

Measurement

Articles 1 - 8 of 8

Full-Text Articles in Physics

Measurement Of The Neutron Lifetime Using A Magneto-Gravitational Trap And In Situ Detection, Robert W. Pattie Jr., Nathan B. Callahan, Chris Cude-Woods, Edith R. Adamek, Leah J. Broussard, Stephen M. Clayton, Scott A. Currie, Eric B. Dees, Xiaoping Ding, Egbert M. Engel, D. E. Fellers, William Fox, Peter Geltenbort, Kevin P. Hickerson, Mark A. Hoffbauer, Anthony T. Holley, A. Komives, Chen Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, Joseph D. Ortiz, John C. Ramsey, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, E. I. Sharapov, S. K. Sjue, Zebo Tang, J. Vanderwerp, Bruce Vogelaar, P. L. Walstrom, Zhehui Wang, Wei Wei, H. L. Weaver, Judith W. Wexler, Tanner L. Womack, Andrew R. Young, B. A. Zeck May 2018

Measurement Of The Neutron Lifetime Using A Magneto-Gravitational Trap And In Situ Detection, Robert W. Pattie Jr., Nathan B. Callahan, Chris Cude-Woods, Edith R. Adamek, Leah J. Broussard, Stephen M. Clayton, Scott A. Currie, Eric B. Dees, Xiaoping Ding, Egbert M. Engel, D. E. Fellers, William Fox, Peter Geltenbort, Kevin P. Hickerson, Mark A. Hoffbauer, Anthony T. Holley, A. Komives, Chen Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, Joseph D. Ortiz, John C. Ramsey, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, E. I. Sharapov, S. K. Sjue, Zebo Tang, J. Vanderwerp, Bruce Vogelaar, P. L. Walstrom, Zhehui Wang, Wei Wei, H. L. Weaver, Judith W. Wexler, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

The precise value of the mean neutron lifetime, tn, plays an important role in nuclear and particle physics and cosmology. It is used to predict the ratio of protons to helium atoms in the primordial universe and to search for physics beyond the Standard Model of particle physics. We eliminated loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls. As a result of this approach and the use of an in …

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Measurement Of Spin-Flip Probabilities For Ultracold Neutrons Interacting With Nickel Phosphorus Coated Surfaces, Zhaowen Tang, Evan Robert Adamek, Aaron Brandt, Nathan Brannan Callahan, Steven M. Clayton, Scott Allister Currie, Takeyasu M. Ito, Mark F. Makela, Yasuhiro Masuda, Christopher L. Morris, Robert Wayne Pattie, John Clinton Ramsey, Daniel J. Salvat, Daniel J. Salvat, Alexander Saunders, Albert R. Young Aug 2016

Measurement Of Spin-Flip Probabilities For Ultracold Neutrons Interacting With Nickel Phosphorus Coated Surfaces, Zhaowen Tang, Evan Robert Adamek, Aaron Brandt, Nathan Brannan Callahan, Steven M. Clayton, Scott Allister Currie, Takeyasu M. Ito, Mark F. Makela, Yasuhiro Masuda, Christopher L. Morris, Robert Wayne Pattie, John Clinton Ramsey, Daniel J. Salvat, Daniel J. Salvat, Alexander Saunders, Albert R. Young

Robert W. Pattie Jr.

We report a measurement of the spin-flip probabilities for ultracold neutrons interacting with surfaces coated with nickel phosphorus. For 50 μm thick nickel phosphorus coated on stainless steel, the spin-flip probability per bounce was found to be βNiPonSS=(3.3−5.6+1.8)×10−6. For 50 μm thick nickel phosphorus coated on aluminum, the spin-flip probability per bounce was found to be βNiPonAl=(3.6−5.9+2.1)×10−6. For the copper guide used as reference, the spin flip probability per bounce was found to be βCu=(6.7−2.5+5.0)×10−6. The results on the nickel phosphorus-coated surfaces may be interpreted as upper limits, yielding βNiPonSS<6.2×10−6 (90% C.L.) and βNiPonAl<7.0×10−6 (90% C.L.) for 50 μm thick …

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Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta Aug 2015

Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta

Joan Carletta

We demonstrate a high throughput, all-electronic Coulter-type sensor with four sensing microapertures to detect and count micro-scale particles. Four particle samples are utilized for this study: polymethacrylate particles 40 µm and 20 µm in diameter, Juniper Scopulorum (Rocky Mountain Juniper) pollen and Cottonwood pollen particles. The two types of pollen particles are roughly 20 µm in diameter. The particles are mixed with deionized water and forced to pass through the microapertures. Voltage pulses across all four apertures are recorded and analysed. Results demonstrate that the sensor can detect and count particles through its four sensing apertures simultaneously. Thus, the counting …

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Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta Apr 2015

Detection And Counting Of Micro Scale Particles And Pollen Using A Multi-Aperture Coulter Counter, Ashish Jagtiani, Jiang Zhe, Jun Hu, Joan Carletta

Dr. Jiang Zhe

We demonstrate a high throughput, all-electronic Coulter-type sensor with four sensing microapertures to detect and count micro-scale particles. Four particle samples are utilized for this study: polymethacrylate particles 40 µm and 20 µm in diameter, Juniper Scopulorum (Rocky Mountain Juniper) pollen and Cottonwood pollen particles. The two types of pollen particles are roughly 20 µm in diameter. The particles are mixed with deionized water and forced to pass through the microapertures. Voltage pulses across all four apertures are recorded and analysed. Results demonstrate that the sensor can detect and count particles through its four sensing apertures simultaneously. Thus, the counting …

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Measurement Of The Half-Life Of The T=1/2 Mirror Decay Of Ne-19 And Its Implication On Physics Beyond The Standard Model, Leah J. Broussard, Henning O. Back, Mitzi S. Boswell, A. S. Crowell, Peter Dendooven, G. S. Giri, Calvin R. Howell, M. F. Kidd, Klaus Jungmann, Wilbert L. Kruithof, A. Mol, Cornelis J. G. Onderwater, Robert W. Pattie Jr., Praveen D. Shidling, M. Sohani, D. J. Van Der Hoek, A. Rogachevskiy, Emil Traykov, Oscar O. Versolato, Lorenz Willmann, Hans W. Wilschut, Andrew T. Young May 2014

Measurement Of The Half-Life Of The T=1/2 Mirror Decay Of Ne-19 And Its Implication On Physics Beyond The Standard Model, Leah J. Broussard, Henning O. Back, Mitzi S. Boswell, A. S. Crowell, Peter Dendooven, G. S. Giri, Calvin R. Howell, M. F. Kidd, Klaus Jungmann, Wilbert L. Kruithof, A. Mol, Cornelis J. G. Onderwater, Robert W. Pattie Jr., Praveen D. Shidling, M. Sohani, D. J. Van Der Hoek, A. Rogachevskiy, Emil Traykov, Oscar O. Versolato, Lorenz Willmann, Hans W. Wilschut, Andrew T. Young

Robert W. Pattie Jr.

The 1 2 þ → 1 2 þ superallowed mixed mirror decay of 19Ne to 19F is excellently suited for high precision studies of the weak interaction. However, there is some disagreement on the value of the half-life. In a new measurement we have determined this quantity to be T1=2 ¼ 17.2832 #1; 0.0051ðstatÞ #1; 0.0066ðsystÞ s, which differs from the previous world average by 3 standard deviations. The impact of this measurement on limits for physics beyond the standard model such as the presence of tensor currents is discussed.

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Superlattice Ultrasonic Generation, Thomas E. Wilson, M. Oehme, E. Kasper, H-J. L. Gossmann Feb 2014

Superlattice Ultrasonic Generation, Thomas E. Wilson, M. Oehme, E. Kasper, H-J. L. Gossmann

Thomas E. Wilson

We report the first experimental evidence for the resonant excitation of coherent high-frequency acoustic phonons in semiconducting doping superstructures by far-infrared laser radiation. After a grating-coupled delta-doped silicon doping superlattice is illuminated with ~1 kW/mm2 nanosecond-pulsed 246 GHz laser radiation, a delayed nanosecond pulse is detected by a superconducting bolometer at a time corresponding to the appropriate time-of-flight for ballistic longitudinal acoustic phonons across the (100) silicon substrate. The absorbed phonon power density in the microbolometer is observed to be ~10 μW/mm2, in agreement with theory. The phonon pulse duration also matches the laser pulse duration. The absence of any …

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Measurement Of The Neutron -Asymmetry Parameter A0 With Ultracold Neutrons, Bradley Plaster, R. Rios, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Steven Clayton, Scott Currie, Bradley W. Filippone, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Anthoney T. Holley, Takeyasu M. Ito, Chenyu Liu, Jingyang Liu, Mark Makela, J. W. Martin, Daniel Melconian, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Margaret L. Pitt, John C. Ramsey, R. Russell, Andy Saunders, R. Schmid, Susan J. Seestrom, Sky Sjue, Walter E. Sondheim, E. Tatar, B. Tipton, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Y. P. Xu, H. Yan, Andrew R. Young, J. Yuan Dec 2011

Measurement Of The Neutron -Asymmetry Parameter A0 With Ultracold Neutrons, Bradley Plaster, R. Rios, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Steven Clayton, Scott Currie, Bradley W. Filippone, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Anthoney T. Holley, Takeyasu M. Ito, Chenyu Liu, Jingyang Liu, Mark Makela, J. W. Martin, Daniel Melconian, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Margaret L. Pitt, John C. Ramsey, R. Russell, Andy Saunders, R. Schmid, Susan J. Seestrom, Sky Sjue, Walter E. Sondheim, E. Tatar, B. Tipton, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Y. P. Xu, H. Yan, Andrew R. Young, J. Yuan

Robert W. Pattie Jr.

We present a detailed report of a measurement of the neutron β-asymmetry parameter A0, the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T 2 × 2π solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages …

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Electric Field And Plasma Density Measurements In The Auroral Electrojet, R. Pfaff, M. C. Kelley, Bela G. Fejer, E. Kudeki, C. W. Carlson, A. Pedersen, B. Hausler Jan 1984

Electric Field And Plasma Density Measurements In The Auroral Electrojet, R. Pfaff, M. C. Kelley, Bela G. Fejer, E. Kudeki, C. W. Carlson, A. Pedersen, B. Hausler

Bela G. Fejer

Intense electrostatic waves in the auroral E region have been detected simultaneously on two payloads launched in a mother-daughter configuration from Kiruna, Sweden. The data sets comprise electric field and density measurements from the ambient (dc) conditions to fluctuations as high as 50 kHz. The dc electric field measured by both payloads was 54 mV/m northwest, which corresponded to an electron drift velocity of 1080 m/s. This electric field drove two-stream waves perpendicular to both B and E observed by both spacecraft throughout an altitude region which agrees quite well with the range predicted by linear two-stream theory. The power …

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