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相关论文: Magnetic trapping of ultracold neutrons

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The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In…

Accurate measurement of the lifetime of the neutron (which is unstable to beta decay) is important for understanding the weak nuclear force and the creation of matter during the Big Bang. Previous measurements of the neutron lifetime have…

The current knowledge of the neutron $\beta$-decay lifetime has come under scrutiny as of late due to large disagreements between recent precise measurements. Measurements using magnetically trapped Ultra-Cold Neutrons (UCNs) offer the…

核实验 · 物理学 2009-02-05 Kent Leung , Oliver Zimmer

We report a new measurement of the neutron lifetime using ultra-cold neutrons stored in a magneto-gravitational trap made of permanent magnets. Neutrons surviving in the trap after fixed storage times have been counted and the trap losses…

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from…

We report a new measurement of the neutron decay lifetime by the absolute counting of in-beam neutrons and their decay protons. Protons were confined in a quasi-Penning trap and counted with a silicon detector. The neutron beam fluence was…

The confinement of ultracold neutrons (UCNs) in a three dimensional magnetic field gradient trap allows for a measurement of the free neutron lifetime with superior control over spurious loss channels and can provide a large kinetic energy…

Measurements of the lifetime of neutrons trapped in a bottle have been consistently shorter than the lifetime measured in neutron beam experiments. With trapping potentials as low as 50 neV and neutron detectors located only at the top of…

高能物理 - 唯象学 · 物理学 2021-02-24 Surjeet Rajendran , Harikrishnan Ramani

We present the results of numerical simulations of the dynamical behavior of trajectories of ultra cold neutrons (UCN) in a magnetic trap. The main goal of our simulations was to optimize the trap parameters in order to minimize the…

核实验 · 物理学 2007-05-23 Vyacheslav N. Gorshkov , Gennady P. Berman

One method of determining the free neutron lifetime involves the absolute counting of neutrons and trapped decay protons. In such experiments, a cold neutron beam traverses a segmented proton trap inside a superconducting solenoid while the…

A measurement of the neutron lifetime $\tau_{n}$ performed by the absolute counting of in-beam neutrons and their decay protons has been completed. Protons confined in a quasi-Penning trap were accelerated onto a silicon detector held at a…

The puzzle remains in the large discrepancy between neutron lifetime measured by the two distinct experimental approaches -- counts of beta decays in a neutron beam and storage of ultracold neutrons in a potential trap, namely, the beam…

核实验 · 物理学 2020-12-02 Wanchun Wei

Thulium atoms are trapped in a magneto-optical trap using a strong transition at 410 nm with a small branching ratio. We trap up to $7\times10^{4}$ atoms at a temperature of 0.8(2) mK after deceleration in a 40 cm long Zeeman slower.…

原子物理 · 物理学 2010-12-27 D. Sukachev , A. Sokolov , K. Chebakov , A. Akimov , S. Kanorsky , N. Kolachevsky , V. Sorokin

The UCN$\tau$ experiment is designed to measure the lifetime $\tau_{n}$ of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines…

Neutron lifetime is one of the most important physical constants which determines parameters of the weak interaction and predictions of primordial nucleosynthesis theory. There remains the unsolved problem of a 3.9{\sigma} discrepancy…

Different geometries for the neutron lifetime measurements by the method of ultracold neutron storage in material traps and additional possibilities for the neutron storage in the magnetic storage ring are considered.

核实验 · 物理学 2011-04-07 Yu. N. Pokotilovski

We observe magnetic trapping of atomic nitrogen (14^N) and cotrapping of ground state imidogen (14^NH, X-triplet-Sigma-). Both are loaded directly from a room temperature beam via buffer gas cooling. We trap approximately 1 * 10^11 14^N…

原子物理 · 物理学 2009-11-13 Matthew T. Hummon , Wesley C. Campbell , Hsin-I Lu , Edem Tsikata , Yihua Wang , John M. Doyle

Present experiments do not exclude that the neutron transforms into some invisible degenerate twin, so called mirror neutron, with an appreciable probability. These transitions are actively studied by monitoring neutron losses in ultra-cold…

高能物理 - 唯象学 · 物理学 2015-06-04 Z. Berezhiani , F. Nesti

In the UCN{\tau} experiment, ultracold neutrons (UCN) are confined by magnetic fields and the Earth's gravitational field. Field-trapping mitigates the problem of UCN loss on material surfaces, which caused the largest correction in prior…

We report the trapping of ultracold 87Rb atoms in a 0.7 micron-period 2D triangular magnetic lattice on an atom chip. The magnetic lattice is created by a lithographically patterned magnetic Co/Pd multilayer film plus bias fields. Rubidium…

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