Cryogenic Particle Accumulation In ATRAP And The First Antihydrogen Production Within A Magnetic Gradient Trap For Neutral Antimatter

2008 ◽  
Author(s):  
C. H. Storry ◽  
A. Carew ◽  
D. Comeau ◽  
E. A. Hessels ◽  
M. Weel ◽  
...  
Keyword(s):  
Magnetic Gradient ◽  
Particle Accumulation ◽  
Antihydrogen Production ◽  
Neutral Antimatter

scholarly journals Sympathetic cooling of positrons to cryogenic temperatures for antihydrogen production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
C. J. Baker ◽  
W. Bertsche ◽  
A. Capra ◽  
C. L. Cesar ◽  
M. Charlton ◽  
...  
Keyword(s):  
High Precision ◽  
Penning Trap ◽  
Dense Plasma ◽  
Bound State ◽  
Low Energy ◽  
Cryogenic Temperatures ◽  
Sympathetic Cooling ◽  
Fundamental Symmetries ◽  
Antihydrogen Production ◽  
Neutral Antimatter

AbstractThe positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be+ ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries.

scholarly journals Impact factor analysis on precision of magnetic gradient full tensor measurement system

AIP Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 045211
Author(s):  
Lei Xu ◽  
Ning Zhang ◽  
Huadong Chen ◽  
Chunsheng Lin ◽  
Xu Li ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Impact Factor ◽  
Measurement System ◽  
Magnetic Gradient

scholarly journals Screening for Effects of Inhaled Nanoparticles in Cell Culture Models for Prolonged Exposure

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 606
Author(s):  
Claudia Meindl ◽  
Kristin Öhlinger ◽  
Verena Zrim ◽  
Thomas Steinkogler ◽  
Eleonore Fröhlich
Keyword(s):  
Prolonged Exposure ◽  
A549 Cells ◽  
Cytokine Release ◽  
Transient Effects ◽  
Particle Uptake ◽  
Particle Accumulation ◽  
Low Concentrations ◽  
Culture Models ◽  
20 Nm ◽  
Inhaled Nanoparticles

Respiratory exposure of humans to environmental and therapeutic nanoparticles repeatedly occurs at relatively low concentrations. To identify adverse effects of particle accumulation under realistic conditions, monocultures of Calu-3 and A549 cells and co-cultures of A549 and THP-1 macrophages in the air–liquid interphase culture were exposed repeatedly to 2 µg/cm2 20 nm and 200 nm polystyrene particles with different functionalization. Particle accumulation, transepithelial electrical resistance, dextran (3–70 kDa) uptake and proinflammatory cytokine secretion were determined over 28 days. Calu-3 cells showed constant particle uptake without any change in barrier function and cytokine release. A549 cells preferentially ingested amino- and not-functionalized particles combined with decreased endocytosis. Cytokine release was transiently increased upon exposure to all particles. Carboxyl-functionalized demonstrated higher uptake and higher cytokine release than the other particles in the A549/THP-1 co-cultures. The evaluated respiratory cells and co-cultures ingested different amounts and types of particles and caused small (partly transient) effects. The data suggest that the healthy cells can adapt to low doses of non-cytotoxic particles.

Factor Analysis on Integrated Error Model of Magnetic Gradient Tensor

2021 ◽  
pp. 1-1
Author(s):  
Lei Xu ◽  
Ning Zhang ◽  
Ming Chang ◽  
Huadong Chen ◽  
Chunsheng Lin ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Error Model ◽  
Gradient Tensor ◽  
Magnetic Gradient ◽  
Integrated Error

scholarly journals Experimental Study on Coherent Structures by Particles Suspended in Half-Zone Thermocapillary Liquid Bridges: Review

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 105
Author(s):  
Ichiro Ueno
Keyword(s):  
Coherent Structures ◽  
Three Dimensional ◽  
Wave Number ◽  
Flow Structures ◽  
Liquid Bridges ◽  
Thermocapillary Effect ◽  
Particle Accumulation ◽  
Azimuthal Wave Number ◽  
Experimental Approaches ◽  
Particle Behaviour

Coherent structures by the particles suspended in the half-zone thermocapillary liquid bridges via experimental approaches are introduced. General knowledge on the particle accumulation structures (PAS) is described, and then the spatial–temporal behaviours of the particles forming the PAS are illustrated with the results of the two- and three-dimensional particle tracking. Variations of the coherent structures as functions of the intensity of the thermocapillary effect and the particle size are introduced by focusing on the PAS of the azimuthal wave number m=3. Correlation between the particle behaviour and the ordered flow structures known as the Kolmogorov–Arnold—Moser tori is discussed. Recent works on the PAS of m=1 are briefly introduced.

scholarly journals MAGNETIC RESONANCE SIGNAL LOSS IN TURBULENT SHEAR FLOW

2002 ◽  
Vol 14 (01) ◽  
pp. 1-11
Author(s):  
LIANG-DER JOU
Keyword(s):  
Shear Flow ◽  
Velocity Fluctuation ◽  
Phase Fluctuation ◽  
Eddy Diffusivity ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Signal Loss ◽  
Flow Shear ◽  
Magnetic Gradient ◽  
Spin Echo Sequence

NMR signal loss due to turbulent shear flow is discussed, and a general expression for the phase fluctuation is derived. In the presence of flow shear, the velocity fluctuation perpendicular to the direction of magnetic gradient and the Reynolds stress can cause loss of MR signal Most of signal loss results from the boundary layer, where the flow shear is strong in turbulent pipe flaw, Half the signal loss within the mixing layer distal to a moderate stenosis is caused by the velocity fluctuation in the direction of magnetic gradient, while the remaining results from the velocity, fluctuation perpendicular to the magnetic gradient. The use of eddy diffusivity for the description of signal dephasing in a spin echo sequence is also addressed; A positive, constant eddy diffusivity can not describe the temporal change of phase fluctuation correctly.

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