共查询到20条相似文献,搜索用时 0 毫秒
1.
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.
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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
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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
6.
X.-P. Huang J.J. Bollinger W.M. Itano J.N. Tan B. Jelenković T.B. Mitchell D.J. Wineland 《Hyperfine Interactions》1998,115(1-4):41-45
We apply rotating electric fields to ion plasmas in a Penning trap to obtain phase-locked rotation about the magnetic field
axis. These plasmas, containing up to 106
9Be+ ions, are laser-cooled to millikelvin temperatures so that they freeze into solids. Single body-centered cubic (bcc) crystals
have been observed by Bragg scattering in nearly spherical plasmas with ≳ 2 × 105 ions. The detection of the Bragg patterns is synchronized with the plasma rotation, so individual peaks are observed. With
phase-locked rotation, the crystal lattice and its orientation can be stable for longer than 30 min or ∼108 rotations.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
A Penning trap system called Lanzhou Penning Trap(LPT) is now being developed for precise mass measurements at the Institute of Modern Physics(IMP).One of the key components is a 7 T actively shielded superconducting magnet with a clear warm bore of 156 mm.The required field homogeneity is 3 × 10-7 over two 1 cubic centimeter volumes lying 220 mm apart along the magnet axis.We introduce a two-step method which combines linear programming and a nonlinear optimization algorithm for designing the multi-section superconducting magnet.This method is fast and flexible for handling arbitrary shaped homogeneous volumes and coils.With the help of this method an optimal design for the LPT superconducting magnet has been obtained. 相似文献
8.
A Penning trap system called Lanzhou Penning Trap (LPT) is now being developed for precise mass measurements at the Institute of Modern Physics (IMP). One of the key components is a 7 T actively shielded superconducting magnet with a clear warm bore of 156 mm. The required field homogeneity is 3×10-7 over two 1 cubic centimeter volumes lying 220 mm apart along the magnet axis. We introduce a two-step method which combines linear programming and a nonlinear optimization algorithm for designing the multi-section superconducting magnet. This method is fast and flexible for handling arbitrary shaped homogeneous volumes and coils. With the help of this method an optimal design for the LPT superconducting magnet has been obtained. 相似文献
9.
H.S. Margolis J. Asada T.V. Back D.J. Bieber F.J. Currell E.G. Myers N. Nakamura S. Ohtani P.K. Oxley M. Sakurai J.D. Silver H. Watanabe 《Hyperfine Interactions》1998,112(1-4):139-142
The presence of the σ-phase in Fe-Cr alloys (eg. Stainless steel) is important in industrial applications and from an academic
point of view. The presence of the σ-phase in these alloys drastically affects their mechanical properties and their resistance
to various corrosive media. In the present investigation Fe-Cr alloys containing different amounts of Mo were prepared and
the transformation to the σ-phase was carried out by isothermally annealing the samples for various periods in an argon atmosphere.
It will be shown that the presence of Mo has a dramatic accelerating effect on the rate of the σ-phase formation in these
alloys.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
高电荷态离子精细结构跃迁波长的精密测量不仅可以检验量子电动力学(quantum electrodynamics,QED)效应、电子关联效应等基本物理模型,还能够为天体物理、聚变等离子体物理甚至高电荷态离子光钟等研究提供关键原子物理数据.本工作基于复旦大学现代物理研究所的高温超导电子束离子阱(SHHtscEBIT)装置,搭建了一套新的光谱校刻系统,并结合内校刻与外校刻的方法对其光谱波长测量的不确定度进行了评估,新的光谱校刻系统在可见光波段引起的波长不确定度最低达到0.002 nm.在此基础上,使用SH-HtscEBIT装置结合新的校刻系统开展了Ar13+离子1s22s22p2P1/2—2P3/2磁偶极跃迁(M1)波长的精密测量,实验测得该跃迁波长为(441.2567±0.0026) nm,是目前SH-HtscEBIT上测量精度最高的实验结果,为下一步开展高电荷态离子超精细分裂和同位素位移等精密测量实验奠定了基础. 相似文献
11.
M. Froese C. Champagne J. R. Crespo López-Urrutia S. Epp G. Gwinner A. Lapierre J. Pfister G. Sikler J. Ullrich J. Dilling 《Hyperfine Interactions》2006,173(1-3):85-92
The precision of atomic mass measurements in a Penning trap is directly proportional to the charge state q of the ion and,
hence, can be increased by using highly charged ions (HCI). For this reason, charge breeding with an electron beam ion trap
(EBIT) is employed at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) on-line facility in Vancouver, Canada. By bombarding
the injected and trapped singly charged ions with an intense beam of electrons, the charge state of the ions is rapidly increased
inside the EBIT. To be compatible with the on-line requirements of short-lived isotopes, very high electron beam current densities
are needed. The TITAN EBIT includes a 6 Tesla superconducting magnet and is designed to have electron beam currents and energies
of up to 5 A and 60 keV, respectively. Once operational at full capacity, most species can be bred into a He-like configuration
within tens of ms. Subsequently, the HCI are extracted, pass a Wien filter to reduce isobaric contamination, are cooled, and
injected into a precision Penning trap for mass measurement. We will present the first results and current status of the TITAN
EBIT, which has recently been moved to TRIUMF after assembly and commissioning at the Max-Planck-Institute (MPI) for Nuclear
Physics in Heidelberg, Germany. 相似文献
12.
Klaus Blaum Dietrich Beck Martin Breitenfeldt Sebastian George Frank Herfurth Alexander Herlert Alban Kellerbauer H.-Jürgen Kluge David Lunney Romain Savreux Stefan Schwarz Lutz Schweikhard Chabouh Yazidjian 《Hyperfine Interactions》2006,171(1-3):83-91
High-precision mass measurements as performed at the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN are an important
contribution to the investigation of nuclear structure. Precise nuclear masses with less than 0.1 ppm relative mass uncertainty
allow stringent tests of mass models and formulae that are used to predict mass values of nuclides far from the valley of
stability. Furthermore, an investigation of nuclear structure effects like shell or sub-shell closures, deformations, and
halos is possible. In addition to a sophisticated experimental setup for precise mass measurements, a radioactive ion-beam
facility that delivers a large variety of short-lived nuclides with sufficient yield is required. An overview of the results
from the mass spectrometer ISOLTRAP is given and its limits and possibilities are described.
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13.
Tomas Fritioff Conny Carlberg Guilhem Douysset Reinhold Schuch Ingmar Bergström 《Hyperfine Interactions》2001,132(1-4):229-242
The Penning trap mass spectrometer SMILETRAP has been considerably improved during the last two years. The helium pressure
has been carefully stabilized and is now independent of irregular air pressure. The temperature of the hyperboloidal precision
trap is stabilized to ±0.03°C. Remaining temperature instabilities are compensated by changes in the current of a warm coil
surrounding the precision trap. The frequency synthesizer is now locked to GPS. This means that it is much easier to accurately
measure resonances during several days. The improvements have demonstrated that in mass doublet measurements with an excitation
time of 1 s it is possible to determine the mass of ions with q/A=1/2 at an uncertainty to a few times of 0.1 ppb, using selected rather than cooled ions. In routine measurements lasting
for one day it is possible to reach a mass uncertainty of 1 ppb. The masses of the following particles and atoms have been
measured with uncertainties in the region 0.3–2 ppb: p, 3H, 3He, 4He, 22Ne, 28Si, 36Ar, 76Ge, 76Se, 86Kr and 133Cs. It has also been shown that though we are using a warm bore the trap pressure is sufficiently low to prevent electron
capture from the rest gas for excitation times of 3 s and for ion charges as high as 50+.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Masashi Monobe Hiroyuki A. Sakaue Daiji Kato Izumi Murakami Hirohisa Hara Tetsuya Watanabe Nobuyuki Nakamura 《X射线光谱测定》2020,49(4):511-514
We present extreme ultraviolet spectra of 3s3p–3s3d transitions in Fe14+ observed with a compact electron beam ion trap. The contributions of indirect excitation via a metastable state and resonant excitation are studied by observing the electron energy dependence of the spectra for the energy range of 60–210 eV. The results indicate that the 3s3d 1D2 level is directly excited from the 3s2 ground state whereas the 3s3d 3D3 level has a large contribution of the indirect excitation via the 3s3p 3P2 metastable state. Comparisons with the theoretical excitation cross sections including MNn resonant excitations show good qualitative agreement with the experimental results for the electron energy dependent features. 相似文献
15.
R. Schuch I. Bergström K. Blaum T. Fritioff Sz. Nagy A. Solders M. Suhonen 《Hyperfine Interactions》2006,173(1-3):73-83
We report here about measurements of reaction and decay Q values by precise determination of pairs of atomic masses. These were performed with the Penning trap mass spectrometer SMILETRAP.
Measurements with Penning traps give reliable and accurate masses, in particular Q values, due to the fact that certain systematic errors to a great deal cancel in the mass difference between the two atoms
defining the Q value. Some Q values that are of fundamental interest will be discussed here, for example, a new Q value for the 6Li (n,γ) 7Li reaction, for the β-decay of tritium, related to properties of the electron neutrino mass, and for the neutrino-less double
β-decay of 76Ge, related to the question of whether the neutrino is a Majorana particle or not. In case of the latter two we report the
most accurate Q values, namely 18,589.8(12) eV for the tritium decay and 2,038.997(46) keV for the neutrino-less double β-decay of 76Ge. 相似文献
16.
Z. Ke W. Shi G. Gwinner K. Sharma S. Toews J. Dilling V. L. Ryjkov 《Hyperfine Interactions》2006,173(1-3):103-111
We present simulations of electron and proton cooling of highly charged ions in a Penning trap, including the potentially
detrimental effects of radiative, dielectronic, and three-body recombination in electron cooling. We show a preliminary design
for a cooler trap accommodating both electron and proton cooling, which will be a component of the TITAN ion-trap facility
under construction at TRIUMF for precision mass measurements of short-lived radioactive nuclei.
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17.
Manuel Vogel Mohammad Sadegh Ebrahimi Zhexi Guo Anahita Khodaparast Gerhard Birkl Wolfgang Quint 《Annalen der Physik》2019,531(5)
The magnetic moment (g‐factor) of the electron is a fundamental quantity in physics that can be measured with high accuracy by spectroscopy in Penning traps. Its value has been predicted by theory, both for the case of the free (unbound) electron and for the electron bound in a highly charged ion. Precision measurements of the electron magnetic moment yield a stringent test of these predictions and can in turn be used for a determination of fundamental constants such as the fine structure constant or the atomic mass of the electron. For the bound‐electron magnetic‐moment measurement, two complementary approaches exist, one via the so‐called “continuous Stern–Gerlach effect”, applied to ions with zero‐spin nuclei, and one a spectroscopic approach, applied to ions with nonzero nuclear spin. Here, the latter approach is detailed, and an overview of the experiment and its status is given. 相似文献
18.
G. Savard R. C. Barber C. Boudreau F. Buchinger J. Caggiano J. Clark J. E. Crawford H. Fukutani S. Gulick J. C. Hardy A. Heinz J. K. P. Lee R. B. Moore K. S. Sharma J. Schwartz D. Seweryniak G. D. Sprouse J. Vaz 《Hyperfine Interactions》2001,132(1-4):221-228
The Canadian Penning Trap (CPT) mass spectrometer is a device used for high-precision mass measurements on short-lived isotopes.
It is located at the ATLAS superconducting heavy-ion linac facility where a novel injection system, the RF gas cooler, allows
fast reaction products to be decelerated, thermalized and bunched for rapid and efficient injection into the CPT. The CPT
spectrometer and its injection system will be described in detail and its unique capabilities with respect to its initial
physics program, concentrating on isotopes around the N=Z line with particular emphasis on isotopes of interest to low-energy tests of the electroweak interaction and the rp-process,
will be highlighted.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
The present work is concerned with the association of a temperature to a single ion stored in a Penning ion trap. Several methods are described which allow to determine the temperature by measurements of the ions cyclotron and axial trapping frequencies. Recent results of a measurement on a hydrogen-like carbon ion 12C5 + by use of mode coupling are presented and possible further applications are discussed.Received: 8 July 2004, Published online: 6 December 2004PACS:
07.20.-n. Thermal instruments and apparatus - 07.20.Dt. Thermometers - 42.50.Lc Quantum fluctuations - 42.50.Vk Mechanical effects of light on ions 相似文献
20.
The excitation of the motion of ions in a Penning trap at twice their cyclotron frequency, 2ν
c
, by means of an azimuthal octupolar RF field has been studied with the LEBIT facility at the NSCL. The possibility of such
an RF octupolar excitation has been verified. Compared to ion excitation at ν
c
by means of quadrupolar fields an increased resolving power is observed in the cyclotron resonance curves, which may have
important implications for Penning trap mass measurements. Numerical simulations have been used to characterize important
properties of this type of excitation in detail and to predict the behavior of the ion motion under realistic conditions.
Good agreement with the experimental results is observed.
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