共查询到20条相似文献,搜索用时 31 毫秒
1.
Ming-Ze Sun Xiao-Hong Zhou Meng Wang Yu-Hu Zhang Yu. A. Litvinov 《Frontiers of Physics》2018,13(6):132112
In recent years, extensive short-lived nuclear mass measurements have been carried out at the Heavy- Ion Research Facility (HIRFL) in Lanzhou using Isochronous Mass Spectrometry (IMS). The obtained mass values have been successfully applied to nuclear structure and astrophysics studies. In this contribution, we give a brief introduction to the nuclear mass measurements at HIRFL-CSR facility. Main technical developments are described and recent results are summarized. Furthermore, we envision the future perspective for the next-generation storage ring facility HIAF in Huizhou. 相似文献
2.
《中国物理C(英文版)》2015,(10)
In this paper, we present direct mass measurements of neutron-rich86 Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry(IMS) method. The new mass excesses of52-54 Sc nuclides are determined to be-40492(82),-38928(114),-34654(540) ke V, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012(AME12).In particular,53 Sc and54Sc are more bound by 0.8 Me V and 1.0 Me V, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N =32 in Sc isotopes. 相似文献
3.
G. Bollen C. Bachelet M. Block D. A. Davies M. Facina C. M. Folden III C. Guénaut J. Huikari E. Kwan A. Kwiatowski D. J. Morrissey G. Pang A. Prinke R. Ringle J. Savory P. Schury S. Schwarz C. Sumithrarachchi T. Sun 《The European physical journal. Special topics》2007,150(1):337-341
The Low-Energy Beam and Ion Trap facility LEBIT at the
NSCL at MSU has demonstrated that rare isotopes produced by
fast-beam fragmentation can be slowed down and prepared for
precision experiments with low-energy beams. High-pressure
gas-stopping was combined with advanced ion manipulation techniques
to carry out these studies with a high-precision 9.4-Tesla Penning
trap mass spectrometer. The spectrometer has been used for a series
of high precision mass measurements of short-lived neutron- and
proton-rich isotopes during the past year. This paper presents an
overview of the LEBIT facility and summarizes the first mass
measurement results. The mass measurements of 81Se, where
ground and isomeric states have been resolved, and of 80As will
be discussed in detail. 相似文献
4.
M.Büscher 《中国物理C(英文版)》2010,34(9)
Selected results from experiments at COSY-Jülich are presented: an attempt to measure the mass of the η meson with high precision (ANKE facility),first steps towards the detection of rare η decays (WASA),and several measurements of KK-pair production (ANKE,COSY-11,MOMO). 相似文献
5.
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.
相似文献
6.
P. Delheij L. Blomeley M. Froese G. Gwinner V. Ryjkov M. Smith J. Dilling 《Hyperfine Interactions》2006,173(1-3):123-131
The TITAN facility at TRIUMF-ISAC will use four ion traps with the primary goal of determining nuclear masses with high precision, particularly for short lived isotopes with lifetimes down to approximately 10 ms. The design value for the accuracy of the mass measurement is 1 ×10???8. The four main components in the facility are an RF cooler/buncher (RFCT) receiving the incoming ion beam, an electron beam ion trap (EBIT) to breed the ions to higher charge states, a cooler Penning trap (CPET) to cool the highly charged ions, and finally the measurement Penning trap (MPET) for the precision mass determination. Additional goals for this system are laser spectroscopy on ions extracted from the RFCT and beta spectroscopy in the EBIT (in Penning trap mode) on ions that are purified using selective buffer gas cooling in the CPET. The physics motivation for the mass measurements are manifold, from unitarity tests of the CKM matrix to nuclear structure very far from the valley of stability, nuclear astrophysics and the study of halo-nuclei. As a first measurement the mass of 11Li will be determined. With a lifetime of 8.7 ms and a demonstrated production rate of 4×104 ions/sec at ISAC the goal for this measurement at TITAN is a relative uncertainty of 5×10???8. This would check previous conflicting measurements and provide information for nuclear theory and models. 相似文献
7.
S. Nath A. Jhingan T. Varughese J. J. Das P. Sugathan N. Madhavan R. Kumar R. P. Singh S. Muralithar R. K. Bhowmik A. K. Sinha 《Physics of Atomic Nuclei》2003,66(8):1523-1527
Recoil mass spectrometers (RMS) are ideal instruments for identifying weakly populated reaction products in the forward angle from heavy-ion reactions amidst an intense beam background. The Heavy Ion Reaction Analyzer (HIRA) at the Nuclear Science Centre (NSC), New Delhi, is one of the few operating first generation RMSs. The features of and physics studies pursued using HIRA are covered in the paper. With the augmentation of the accelerator facilities at NSC, a second generation RMS combined with a gas-filled separator is planned. The design details of the new facility, Hybrid Recoil Mass Analyzer (HYRA), are presented. HYRA will be operated either stand-alone or in conjunction with a Large Gamma Array (LGA) at its target position. Physics studies planned with these forthcoming facilities are outlined. 相似文献
8.
C. Rauth D. Ackermann G. Audi M. Block A. Chaudhuri S. Eliseev F. Herfurth F. P. Heßberger S. Hofmann H.-J. Kluge A. Martín G. Marx M. Mukherjee J. B. Neumayr W. R. Plaß S. Rahaman D. Rodríguez L. Schweikhard P. G. Thirolf G. Vorobjev C. Weber 《The European physical journal. Special topics》2007,150(1):329-335
9.
S. Schwarz C. Bachelet M. Block G. Bollen D. Davies M. Facina C. M. Folden III C. Guénaut J. Huikari E. Kwan A. A. Kwiatkowski D. J. Morrissey G. Pang A. Prinke R. Ringle J. Savory P. Schury C. Sumithrarachchi T. Sun 《Hyperfine Interactions》2006,173(1-3):113-122
The low-energy beam and ion trap facility LEBIT at the NSCL at MSU has demonstrated that rare isotopes produced by fast-beam
fragmentation can be slowed down and prepared such that precision experiments with low-energy beams are possible. For this
purpose high-pressure gas-stopping is employed combined with advanced ion manipulation techniques. Penning trap mass measurements
on short-lived rare isotopes have been performed with a 9.4 T Penning trap mass spectrometer. Examples include 66As, which has a half-live of only 96 ms, and the super-allowed Fermi-emitter 38Ca, for which a mass accuracy of 8 ppb (280 eV) has been achieved. The high accuracy of this new mass value makes 38Ca a new candidate for the test of the conserved vector current hypothesis.
相似文献
10.
The FRS-ESR facility at GSI provides one of the most efficient methods for direct mass measurements. In the present experiment,
exotic nuclei were produced via fragmentation of 152Sm projectiles in a thick beryllium target at 500-600 MeV/u, separated in-flight with the fragment separator FRS, and injected
into the storage-cooler ring ESR. Time-resolved Schottky Mass Spectrometry was applied for mass measurements of stored and
electron-cooled bare and few-electron ions. 373 different nuclides were identified by means of the spectra of their revolution
frequencies. Masses for 18 nuclides (84Zr, 92Ru, 94Rh, 107,108,110Sb, 111,112,114I, 118Ba, 122,123La, 124Ce, 127Pr, 129Nd, 132Pm, 134Sm, 137Eu) have been determined for the first time. Masses for 111,112I and 113Xe have been obtained via known α-decay energies. The experiment and first results will be presented. 相似文献
11.
V. V. Simon P. Delheij J. Dilling Z. Ke W. Shi G. Gwinner 《Hyperfine Interactions》2011,199(1-3):151-159
TITAN is an on-line facility dedicated to precision experiments with short-lived radioactive isotopes, in particular mass measurements. The achievable resolution on mass measurement, which depends on the excitation time, is limited by the half life of the radioactive ion. One way to bypass this is by increasing the charge state of the ion of interest. TITAN has the unique capability of charge-breeding radioactive ions using an electron-beam ion trap (EBIT) in combination with Penning trap mass spectrometry. However, the breeding process leads to an increase in energy spread, ??E, which in turn negatively influences the mass uncertainty. We report on the development of a cooler Penning trap which aims at reducing the energy spread of the highly charged ions prior to injection into the precision mass measurement trap. Electron and proton cooling will be tested as possible routes. Mass selective cooling techniques are also envisioned. 相似文献
12.
G. Bollen F. Ames G. Audi D. Beck J. Dilling O. Engels S. Henry F. Herfurth A. Kellerbauer H.-J. Kluge A. Kohl E. Lamour D. Lunney R. B. Moore M. Oinonen C. Scheidenberger S. Schwarz G. Sikler J. Szerypo C. Weber 《Hyperfine Interactions》2001,132(1-4):213-220
Penning trap mass spectrometry has reached a state that allows its application to very short-lived nuclides available from
various sources of radioactive beams. Mass values with outstanding accuracy are achieved even far from stability. This paper
illustrates the state of the art by summarizing the status of the ISOLTRAP experiment at ISOLDE/CERN. Furthermore, results
of mass measurements on unstable rare earth isotopes will be given.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
加速器质谱是近年来蓬勃发展的一种十分活跃的核分析技术,其应用涉及环境科学、地质学、核物理及天体物理、生物医学等多个领域。中国原子能科学研究院的加速器质谱装置自从1989年建立至今,已经对^36Cl,^10Be,^129I,^26Al,^79Se和^41Ca等多种核素进行了成功测量。介绍了中国原子能科学研究院的加速器质谱计系统、核素的测量原理及几种相关核素的成功应用。The Accelerator Mass Spectrometry facility at the China Institute of Atomic Energy was established in 1989. The measurement methods for interesting nuclides such as ^36Cl, ^10Be, ^129I, ^26Al, ^79Se and ^41Ca etc. have been established and studies on their applications have been carried out. The facility and some interesting applications are briefly introduced. 相似文献
14.
Secondary electron time detector for mass measurements at CSRe 总被引:1,自引:0,他引:1
TU Xiao-Lin WANG Meng HU Zheng-Guo XU Hu-Shan GUO Zhong-Yan MAO Rui-Shi XIAO Guo-Qing ZHANG Hong-Bin ZANG Yong-Dong YUE Ke 《中国物理C(英文版)》2010,34(3)
The Isochronous Mass Spectrometry is a high accurate mass spectrometer. A secondary electrons time detector has been developed and used for mass measurements. Secondary electrons from a thin carbon foil are accelerated by an electric field and deffected 180° by a magnetic field onto a micro-channel plate. The time detector has been tested with alpha particles and a time resolution of 197 ps (FWHM) was obtained in the laboratory. A mass resolution around 8×10-6 for m/m was achieved by using this time detector in a pilot mass measurement experiment. 相似文献
15.
Herfurth F Dilling J Kellerbauer A Audi G Beck D Bollen G Kluge HJ Lunney D Moore RB Scheidenberger C Schwarz S Sikler G Szerypo J 《Physical review letters》2001,87(14):142501
Mass measurements on (33,34,42,43)Ar were performed using the Penning trap mass spectrometer ISOLTRAP and a newly constructed linear Paul trap. This arrangement allowed us, for the first time, to extend Penning trap mass measurements to nuclides with half-lives below one second ( 33Ar: T(1/2) = 174 ms). A mass accuracy of about 10(-7) (deltam approximately 4 keV) was achieved for all investigated nuclides. The isobaric multiplet mass equation was checked for the A = 33, T = 3/2 quartet and found to be inconsistent with the generally accepted quadratic form. 相似文献
16.
质量是原子核的基本性质之一,在核物理和核天体物理中都有重要的应用。原子核质量测量是目前核物理研究的一个前沿热点课题,国际上各个核物理实验室积极发展新设备和新技术,在短寿命放射性核素测量和超高精度质量测量方面取得了重要进展,本文对此进行了总结评述。在兰州重离子加速器冷却储存环(HIRFL-CSR)上利用等时性质量谱仪测量了一些原子核的质量,本文对其在测量精度、核态最短寿命等前沿进展做了简要介绍,并介绍了正在发展的双飞行时间质量谱仪。原子质量评估收集所有与原子核质量相关的实验数据,经过评估后推荐出质量值及相应误差。原子质量评估AME2016于2017年3月发表,为科技工作者提供基准数据。Mass is a fundamental property of the atomic nucleus. Nuclear mass data play an important role in nuclear physics and nuclear astrophysics. Thanks to the developments of novel mass spectrometers and radioactive nuclear beam facilities, the experimental knowledge of nuclear masses has been continuously expanding along two main directions, including:measurements aimed at high-precision mass values and at the most exotic nuclei far from the stability. The latest progress are reviewed in the paper. In the past few years, mass measurements of short-lived nuclides were performed using isochronous mass spectrometry based on the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou(HIRFL-CSR). The progresses on the frontiers of short half-life and high precision are introduced. The Atomic Mass Evaluation (AME) is the most reliable source for the comprehensive information related to the atomic (nuclear) masses. The latest version of the AME, i.e., AME2016, was published in March, 2017, serving the research community with the benchmark data. 相似文献
17.
C. Hugenschmidt K. Schreckenbach M. Stadlbauer B. Straßer 《Applied Surface Science》2006,252(9):3098-3105
The in-pile positron source NEutron induced POsitron source MUniCh (NEPOMUC) of the new Munich research reactor FRM-II is now operated at the nominal reactor power of 20 MW. Recently, intensity and positron beam profile measurements were performed at 30 eV and 1 keV, respectively. For this purpose, NaI-scintillators detect the 511 keV γ-radiation of positrons that annihilate at a removable target in the beam line. The beam profile is determined with a micro-channel plate detector and a CCD-camera. In the present arrangement of NEPOMUC's instrumentation the positron beam is connected to a coincident Doppler broadening (CDB) facility and to a positron induced Auger electron spectroscopy (PAES) analysis chamber. First experiments were carried out in order to show the performance of these new spectrometers. An overview of the positron beam facility is given and first experimental results of PAES are presented. 相似文献
18.
The comparison of mass and energy variation in a nuclear reaction allows an experimental verification of Einstein’s energy
- mass equivalence principle. Mass measurements are performed in a high precision Penning trap and yield values in unified
atomic mass units. The energies of emitted gamma radiation are determined via Laue-diffraction with perfect crystals. The
according values of the gamma ray wave lengths are expressed in units of the crystal lattice constant. The comparison of masses
and wave lengths requires a conversion factor, which represents the unified atomic mass unit within the SI unit system. The
latter is given by the molar Planck constant N
A
h, which itself is known via its relation to the fine structure constant. In the present paper we report on measurements carried
out until 2003 with an uncertainty level of 4 ⋅ 10-7. We discuss the main limitations of these experiments and outline the possibilities for future measurements at the 10-8 level. Such measurements would allow a direct representation of the unified atomic mass unit in terms of a Compton frequency
and are of utmost importance for a future re-definition of the kilogram mass unit. 相似文献
19.
Jens Dilling 《Hyperfine Interactions》2010,196(1-3):219-223
The present report gives a short summary of current work at the TITAN mass spectrometer, including on-line mass measurements and systematic studies. A list of recent references for work published is given. 相似文献
20.
Pioneering experiments with stored and cooled exotic nuclei at relativistic energies have been performed using the combination
of the fragment separator FRS with the storage-cooler ring ESR. Exotic nuclei created in peripheral collisions are spatially
separated in-flight and injected into the storage ring for high-precision mass and unique lifetime measurements. Lifetimes
of stored bare and few-electron nuclei have been measured to study the influence of the electron density on the β decay. This
condition, relevant for stellar plasma, can now be systematically investigated in the laboratory for the first time. Characteristic
experiments of the present FRS-ESR system are presented and perspectives for a next-generation facility are briefly outlined.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献