63 research outputs found
Continuous density measurement of atomic hydrogen by means of a bolometer
We developed a device which allows continuous measurement of the density of low‐temperature stabilized atomic hydrogen by means of a bolometer. This density monitor was tested in a large open‐storage cell during microwave‐induced extraction of polarized atoms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70391/2/RSINAK-62-1-251-1.pd
A helium film coated quasi‐parabolic mirror to focus a beam of ultra‐cold spin polarized atomic hydrogen
A 350 mK helium‐4‐coated mirror was used to increase the intensity of an ultra‐cold electron‐spin‐polarized atomic hydrogen beam. The mirror uses the observed specular reflection of atomic hydrogen from a superfluid‐helium‐covered surface. A quasi‐parabolic polished copper mirror was installed with its focus at the 5 mm diameter exit aperture of an atomic hydrogen stabilization cell in the gradient of an 8 T solenoid field. The four‐coned mirror shape, which was designed specifically for operation in the gradient, increased the beam intensity focused by a sextupole magnet into a compression tube detector by a factor of about 7.5.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87512/2/40_1.pd
Cryopumping of atomic hydrogen
The pumping speed for the cryopumping of an atomic hydrogen beam was measured. Measurements were made for cryocondensation, cryosorption, and differential pumping. The pumping speed for atomic hydrogen was observed to be much smaller than the pumping speed for molecular hydrogen. It is believed that this is due to the energy released during the recombination of the atomic hydrogen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69754/2/RSINAK-62-11-2738-1.pd
Ultra-cold methods for polarized atomic hydrogen
Using the ultra-cold electron-spin-polarized atomic hydrogen technique, one can produce a slow monochromatic beam for use as a polarized jet target. We will first review the development of the ultra-cold technique and then discuss the recent progress on Michigan’s Mark-II ultra-cold proton-spin-polarized hydrogen jet target. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87438/2/119_1.pd
Michigan ultra-cold polarized atomic hydrogen jet target
To study spin effects in high energy collisions, we are developing an ultra-cold high-density jet target of proton-spin-polarized hydrogen atoms. The target uses a 12 Tesla magnetic field and a 0.3 K separation cell coated with superfluid helium-4 to produce a slow monochromatic electron-spin-polarized atomic hydrogen beam, which is then focused by a superconducting sextupole into the interaction region. In recent tests, we studied a polarized beam of hydrogen atoms focused by the superconducting sextupole into a compression tube detector, which measured the polarized atoms’ intensity. The Jet produced, at the detector, a spin-polarized atomic hydrogen beam with a measured intensity of about 2.8⋅1015 H s−12.8⋅1015Hs−1 and a FWHM area of less than 0.13 cm2. This intensity corresponds to a free jet density of about 1⋅1012 H cm−31⋅1012Hcm−3 with a proton polarization of about 50%. When the transition RF unit is installed, we expect a proton polarization higher than 90%. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87742/2/856_1.pd
Polarized Atomic Hydrogen Beam Tests in the Michigan Ultra‐Cold Jet Target
Progress on the Michigan ultra‐cold proton‐spin‐polarized atomic hydrogen Jet target is presented. We describe the present status of the Jet and some beam test results. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87681/2/872_1.pd
Status of the Michigan Ultra‐Cold Spin‐Polarized Hydrogen Jet
Progress on the Michigan ultra‐cold proton‐spin‐polarized atomic‐hydrogen Jet target is presented. We describe the present status of the Jet and some beam test results. © 2004 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87591/2/639_1.pd
Status on the Michigan‐MIT ultra‐cold polarized hydrogen jet target
Progress on the Mark‐II ultra‐cold polarized atomic hydrogen gas Jet target for the experiments NEPTUN‐A and NEPTUN at UNK is presented. We describe the performance and the present status of different components of the jet.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87525/2/698_1.pd
Polarized atomic hydrogen beam studies in the Michigan ultra-cold jet
Studies of an ultra-cold jet of polarized hydrogen atoms are described. This atomic beam is formed by the acceleration of cold (0.3 K) atoms emerging from a region of high magnetic field (12 T). The maximum measured density was about 1012 atoms cm−3.1012atomscm−3. The beam’s full width half maximum size was less than 4 mm. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87560/2/674_1.pd
Assessment of the Saturation Characteristics of Reservoir Using Core Analysis Data and Relative Permeability Curves
Контакт нефть (газ) – вода в природных коллекторах нельзя назвать чётким, переход от нефтегазоносной к водоносной части пласта происходит постепенно на некотором интервале, который называется переходной зоной. В зависимости от геологического характера пласта и физико-химических свойств нефти и пластовой воды она имеет мощность от одного до десятка метров. Оценки остаточной и текущей водонасыщенности в зоне предельного нефтенасыщения, критической водонасыщенности на уровне ВНК, нефтенасыщенности пласта в переходной зоне при известном расстоянии от ВНК были целью проведённых исследований.In the reservoir, an oil – water contact (OWC) is commonly not fairly sharp. This is a transition zone, where the oil-water content varies gradually. A thickness of the transition zone may be from meter up to ten meters depending on geological characteristics of reservoir rock, and physical and chemical properties of oil and stratal water. The main aim of this work is an estimation of remaining and current water saturation in the zone of critical oil saturation, critical water saturation at the oil-water contact zone, and oil saturation at different distance from the OWC
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