共查询到20条相似文献,搜索用时 15 毫秒
1.
H. Imajo K. Hayasaka R. Ohmukai M. Watanabe S. Urabe 《Applied physics. B, Lasers and optics》1995,61(3):285-289
Be+ ions trapped in a Penning trap are laser-cooled to about 10 mK. The excitation spectra of ion clouds containing about 500 ions are obtained by scanning the frequency of the cooling laser and discontinuities in these spectra are observed because of phase transitions. When the cooled ions are heated electrically by applying an rf voltage, no phase transition occurs and the spectra become continuous. Two-dimensional measurement of the ion clouds is carried out and the abrupt change in the shape of the ion cloud due to the phase transition is observed. When many ions are trapped and cooled, the phase transition occurs partially and a transient state where two states are mixed can be observed. The static properties of the ions are also measured by using an additional probe laser and the results of experimental measurements are compared with theoretical predictions. 相似文献
2.
Sz. Nagy T. Fritioff A. Solders R. Schuch M. Björkhage I. Bergström 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(1):1-4
High-precision mass measurements on lithium-like and hydrogen-like 40Ca-ions are reported. The obtained mass of the hydrogen-like and lithium-like ion is 39.952181819(29) u and 39.953272223(24) u,
respectively. The corresponding mass of the 40Ca atom is 39.962590858(22) u. This new value has a precision ten times higher than the literature value. 相似文献
3.
K. Toyoda H. Kataoka Y. Kai A. Miura M. Watanabe S. Urabe 《Applied physics. B, Lasers and optics》2001,72(3):327-330
Rare calcium isotope ions, 42Ca+ and 44Ca+, were efficiently separated from a laser-cooled ionic cloud in a linear Paul trap which was loaded from an atomic source
of a natural isotope mixture of calcium, in spite of their negligibly small abundances (0.647% and 2.086%, respectively) compared
with that of 40Ca (96.94%). Selective heating and cooling that arise from the isotope shifts were mainly used for the elimination of the
isotopes; selective heating and cooling enable flexible separation when combined with other mechanisms such as the inherent
mass selectivity of RF traps.
Received: 7 July 2000 / Published online: 10 January 2001 相似文献
4.
N. D. Naumov 《Russian Physics Journal》1994,37(7):612-614
An automodel solution of self-consistent equations for an ellipsoidal cluster of Coulomb particles in a Penning trap is obtained.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 18–21, July, 1994. 相似文献
5.
Evaporative cooling of singly charged ions in a Penning trap is studied. The ions are created by in-situ electron bombardment of hydrogen molecules and trapped in a cylindrical Penning trap. Cooling of the ions is observed by their axial motion after trapping of a few hundred milliseconds. The ions temperature decreases by a factor of more than 6 in 800 ms, while the bunch density of the coldest ions increases by up to a factor of 10. By studying the time constants of the dependence of ion loss and axial temperature on the magnetic field strength, we exclude the effects of ions loss through the cyclotron motion on the axial ion temperature. 相似文献
6.
We describe the construction of a novel compact Penning trap from strong permanent magnets for trapping light ions. Our cylindrically symmetric, iron-free magnetic configuration allows fully analytical treatment, is easy to handle and to optimize. The magnetic field inhomogeneity is less than 1% in a volume of 1 cm3 at 0.7 T. The stored H+ and H
2
+
ions in this trap are detected electrically by the rf absorption method. The charge density, total number and storage time of the trapped ions are measured.Dedicated to H. Walther on the occasion of his 60th birthday 相似文献
7.
C. Lichtenberg G. Marx G. Tommaseo P.N. Ghosh G. Werth 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(1):29-32
On the basis of a macroscopic ground state population it was argued recently that Bose-Einstein condensation should occur
in a one-dimensional harmonic potential. We examine this situation by drawing analogies to bosons in a two-dimensional box,
where the thermodynamic limit is well-defined. We show that in both systems although the ground state populations show sharp
onsets at the critical temperature, the behaviour of the specific heat is analytic, which proves the absence of a phase transition
in these systems.
Received: 17 February 1997 / Revised: 3 September 1997 / Accepted: 13 October 1997 相似文献
8.
F. Pereira Dos Santos F. Perales J. Léonard A. Sinatra Junmin Wang F. Saverio Pavone E. Rasel C.S. Unnikrishnan M. Leduc 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):15-22
We present experimental results on the two-body loss rates in a magneto-optical trap of metastable helium atoms. Absolute
rates are measured in a systematic way for several laser detunings ranging from -5 to -30 MHz and at different intensities,
by monitoring the decay of the trap fluorescence. The dependence of the two-body loss rate coefficient β on the excited state
( 23
P
2) and metastable state ( 23
S
1) populations is also investigated. From these results we infer a rather uniform rate constant K
sp = (1±0.4)×10-7 cm3/s.
Received 8 September 2000 and Received in final form 19 December 2000 相似文献
9.
Imperfections in the design or implementation of Penning traps may give rise to electrostatic perturbations that introduce nonlinearities in the dynamics. In this paper we investigate, from the point of view of classical mechanics, the dynamics of a single ion trapped in a Penning trap perturbed by an octupolar perturbation. Because of the axial symmetry of the problem, the system has two degrees of freedom. Hence, this model is ideal to be managed by numerical techniques like continuation of families of periodic orbits and Poincaré surfaces of section. We find that, through the variation of the two parameters controlling the dynamics, several periodic orbits emanate from two fundamental periodic orbits. This process produces important changes (bifurcations) in the phase space structure leading to chaotic behavior. 相似文献
10.
J.P. Salas M. I narrea A.I. Pascual 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(1):45-54
In the frame work of classical mechanics, we study the nonlinear dynamics of a single ion trapped in a Penning trap perturbed
by an electrostatic sextupolar perturbation. The perturbation is caused by a deformation in the configuration of the electrodes.
By using a Hamiltonian formulation, we obtain that the system is governed by three parameters: the z-component of the canonical angular momentum P
φ - which is a constant of the motion because the perturbation we assume is axial-symmetric -, the parameter δ that determines
the ratio between the axial and the cyclotron frequencies, and the parameter a which indicates how far from the ideal design the electrodes are. We study the case P
φ = 0. By means of surfaces of section, we show that the phase space structure is made of three fundamental families of orbits:
arch, loop and box orbits. The coexistence of these kinds of orbits depends on the parameter δ. The escape is also explained on the basis of
the shape of the potential energy surface as well as of the phase space structure.
Received 6 September 2001 / Received in final form 19 March 2002 Published online 28 June 2002 相似文献
11.
F. Galve P. Fernández G. Werth 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):201-204
We demonstrate experimentally the confinement of
electrons in a novel planar Penning trap. Measurement of the
eigenfrequencies of the trapped electron cloud exhibits similar
behaviour as in conventional 3-dimensional penning traps. The trap
may be of future use in quantum computing schemes using single
cold electrons. 相似文献
12.
A Penning trap consisting of concentric ring electrodes on a substrate and a magnetic field perpendicular to the substrate
plane has been loaded with electrons. In order to demonstrate the performance of the trap we have measured the motional frequencies
of the trapped electrons. Frequencies, line shape and width agree well with simulations. Miniaturization of the device is
at hand which opens novel possibilities for application in quantum computing.
Contribution presented at the TCP06, Vancouver Island, 2006-09-21 相似文献
13.
A. Lassesson N. Walsh F. Martinez A. Herlert G. Marx L. Schweikhard 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,34(1-3):73-77
Fullerene dianions in the range C702- to C902- have been created
by subjecting trapped fullerene monoanions to low energy electrons in
a Penning trap. The dianion production was found to be a function of the
trapping-potential depth and the time of interaction between the simultaneously
stored monoanions
and electrons. Under similar conditions the dianion yield depends on the size of
the
fullerenes with more than 10% of the trapped C90- ions forming dianions while
the corresponding relative yield for C702- was less than 0.1%. The
large difference can be explained by the repulsive Coulomb barrier
and the second electron affinity of the fullerenes. 相似文献
14.
An antiproton cloud cooled at 4.2 K in a Penning trap can be further cooled by adiabatic reduction of the trap magnetic and
electric fields. It will be shown that the temperature can be reduced by two orders of magnitude. This cooling method may
be useful to obtain ultra-low energy antiprotons for the measurement of their gravitational properties and the production
of ultra-low energy antihydrogen atoms. 相似文献
15.
16.
David von Lindenfels Manuel Vogel Wolfgang Quint Gerhard Birkl Marco Wiesel 《Hyperfine Interactions》2014,227(1-3):197-207
We have conceived, built and operated a ’half-open’ cylindrical Penning trap for the confinement and laser spectroscopy of highly charged ions. This trap allows fluorescence detection employing a solid angle which is about one order of magnitude larger than in conventional cylindrical Penning traps. At the same time, the desired electrostatic and magnetostatic properties of a closed-endcap cylindrical Penning trap are preserved in this configuration. We give a detailed account on the design and confinement properties, a characterization of the trap and show first results of light collection with in-trap produced highly charged ions. 相似文献
17.
Penning traps are powerful instruments for the precise and accurate mass determination of rare isotopes. At present, many Penning trap facilities installed at radioactive beam facilities provide key data for nuclear astrophysics, for the study of nuclear structure evolution far from stability, and the test of fundamental interactions. This article summarizes the present status and current limits in the field of high-precision Penning trap mass measurements on short-lived exotic ions. 相似文献
18.
F. Herfurth K. Blaum S. Eliseev O. Kester H.-J. Kluge S. Koszudowski C. Kozhuharov G. Maero D. Neidherr W. Quint S. Schwarz S. Stahl G. Vorobjev 《Hyperfine Interactions》2006,173(1-3):93-101
A decelerator will be installed at GSI in order to provide and study heavy nuclei without or with only few electrons at very
low energies or even at rest. Highly-charged ions will be produced by stripping at relativistic energies. After electron cooling
and deceleration in the Experimental Storage Ring (ESR) the ions are ejected out of the storage ring at 4 MeV/u and further
decelerated in a combination of linear accelerator structures operated in reverse. Finally, they are injected into a Penning
trap where the ions are cooled to 4 K by electron cooling in combination with resistive cooling. From here, the ions can be
transferred in a quasi DC or in a pulsed mode to different experimental setups. This article describes the technical concepts
of this project focused on the Penning trap.
相似文献
19.
J. W. Zhang S. G. Wang K. Miao Z. B. Wang L. J. Wang 《Applied physics. B, Lasers and optics》2014,114(1-2):183-187
A transportable microwave frequency standard based on laser-cooled 113Cd+ ions is introduced, and its working principle and potential performance are discussed. Based on the experimental setup developed at JMI, the frequency of the ground-state hyperfine splitting of 113Cd+ is measured to within milliHertz uncertainty and its frequency stability is obtained. 相似文献
20.
报道了在Penning阱中检测与确认Hn 团簇离子的方法,介绍了离子在阱中的运动,重点分析了离子存储条件、离子的产生与探测、离子信号的放大与检波以及离子谱的分辨. 相似文献