نتایج جستجو برای: 3he

تعداد نتایج: 1796  

Journal: :The Astrophysical Journal 2022

We report the first direct measurement of helium isotope ratio, 3He/4He, outside Local Interstellar Cloud, as part science verification observations with upgraded CRyogenic InfraRed Echelle Spectrograph (CRIRES). Our determination 3He/4He is based on metastable HeI* absorption along line-of-sight towards Tet02 Ori A in Orion Nebula. measure a value 3He/4He=(1.77+/-0.13)x10^{-4}, which just ~40 ...

1997
J. A. Sauls

Superfluid 3He confined in aerogel offers a unique chance to study the effects of a short mean free path on the properties of a well defined superfluid Fermi liquid with anisotropic pairing. Transport coefficients and collective excitations, e.g. longitudinal sound, are expected to react sensitively to a short mean free path and to offer the possibility for testing recently developed models for...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2008
Yuji Sano Taichi Tokutake Naoto Takahata

We have developed an analytical system to measure atmospheric 3He/4He ratios precisely by using a static vacuum operation mass spectrometer and an ultrahigh-vacuum purification line. After purification of the sample, helium was introduced into the mass spectrometer. Ion beams of 3He and 4He were measured at the same time by a double collector system. A resolving power of about 700 at the 5% lev...

Journal: :Physical review letters 2000
H Kurki-Suonio E Sihvola

We consider the effect of a small-scale matter-antimatter domain structure on big bang nucleosynthesis and place upper limits on the amount of antimatter in the early universe. For small domains, which annihilate before nucleosynthesis, this limit comes from underproduction of 4He. For larger domains, the limit comes from 3He overproduction. Since most of the 3He from &pmacr; 4He annihilation a...

1997
J. R. Johnson A. K. Thompson T. E. Chupp T. B. Smith N. R. Newbury Joseph Henry

A large-scale high-pressure gaseous 3He polarized target has been developed for use with a high-intensity polarized electron beam at the Stanford Linear Accelerator Center. This target was used successfully in an experiment to study the spin structure of the neutron. The target provided an areal density of about 7×1021 nuclei/cm2 and operated at 3He polarizations between about 30% and 40% for t...

2014
J. S. Xia

We present a new simplified derivation of the effect of lattice relaxation that accompanies the quantum tunneling of 3He impurities in solid 4He on the nuclear spin-lattice relaxation of the 3He impurities for very low impurity concentrations. As a result of the larger zero point motion of the 3He impurity compared to the 4He atoms, a significant lattice distortion accompanies the impurity as i...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان 1378

در این پایان نامه رفتار پلاسمای انبساطی در یک حفره در راکتور گداخت d-3he مورد تحلیل قرار گرفته است . یک میدان مغناطیسی درون حفره جهت کند کردن و منحرف کردن یونهای پلاسما به کار می رود. شبیه سازی هیبرید ذره نشان می دهد که آهنگ رشد ناپایداری رایلی - تیلور آهسته است و دیواره راکتور آسیب نخواهد دید. بوسیله روش ذره در سلول چگونگی تحول زمانی یونهای پلاسما کنترل می شود. این مطالعه بوسیله یک طرح فرضی از...

Journal: :The Astrophysical Journal 2022

Standard stellar evolution models that only consider convection as a physical process to mix material inside of stars predict the production significant amounts 3He in low-mass (M < 2 Msun), with peak abundances 3He/H ~ few x 10-3 by number. Over life-time Galaxy, this ought produce diminish increasing Galactocentric radius. Observations 3He+ HII regions throughout Galactic disk, however, revea...

Journal: :Physical review letters 2008
P Corboz L Pollet N V Prokof'ev M Troyer

Using first-principles simulations for the probability density of finding a 3He atom in the vicinity of the screw dislocation in solid 4He, we determine the binding energy to the dislocation nucleus E(B)=0.8+/-0.1 K and the density of localized states at larger distances. The specific heat due to 3He features a peak similar to the one observed in recent experiments, and our model can also accou...

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