Search results for "ATOMIC MASS"
showing 10 items of 103 documents
Laser desorption/ionization cluster studies for calibration in mass spectrometry
2003
Precise mass calibration is mandatory in many fields of mass spectrometry. We have performed laser desorption/ionization cluster studies with a MALDI-TOF mass spectrometer on gold and fullerene targets to produce atomic clusters. These investigations demonstrate that clusters are ideally suited for this purpose. Pulsed N 2 -laser and Nd:YAG-laser ablation was used to produce positively as well as negatively charged clusters. Earlier observations of dianionic metal clusters are confirmed. First results from the tandem Penning trap mass spectrometer ISOLTRAP using carbon clusters as mass references show how carbon clusters can be applied to precision mass spectrometry by providing absolute ma…
High-precision mass measurement of $^{168}$Yb for verification of nonlinear isotope shift
2020
The absolute mass value of $^{168}$Yb has been directly determined with the JYFLTRAP Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility. A more precise value of the mass of $^{168}$Yb is needed to extract possible signatures of beyond standard model physics from high-precision isotope shift measurements of Yb atomic transition frequencies. The measured mass-excess value, ME($^{168}$Yb) = $-$61579.846(94) keV, is 12 times more precise and deviates from the Atomic Mass Evaluation 2016 value by 1.7$\sigma$. The impact on precision isotope shift studies of the stable Yb isotopes is discussed.
VAKUUMWAAGEN Teil 1: Einleitung und Makrowaagen
1997
Waagen, bei denen sich das zu wagende Gut im Vakuum befindet, werden als Vakuumwaagen bezeichnet. Makrowaagen sind fur Lasten von mehr als 100 g ausgelegt. Zum Vergleich von Masseprototypen ohne Auftrieb wurden Vakuum-Komparatorwaagen entwickelt. Grose Vakuumwaagen werden zur Molekulargewichtsbestimmung und zur Messung der Gasdichte verwendet. Fur chemische Untersuchungen unter reduziertem Gasdruck und zur thermogravimetrischen Analyse werden Vakuum-Analysenwaagen mit elektrischer Meswerterfassung eingesetzt. Zur Steuerung von Produktionsprozessen in kontrollierter Atmosphare dienen Wagezellen unterschiedlicher Bauart. Balances destined for weighing of goods in vacuum are labeled as vacuum …
Experimental studies at JYFLTRAP
2007
JYFLTRAP is a Penning trap system at the accelerator laboratory in Jyvaskyla, Finland that enables high-precision experiments with stored, exotic species that are produced at the IGISOL facility. On one hand, these can be performed within the trap itself, like e.g. mass spectrometry. On the other hand, the trap can be used to provide the highly purified species for further experiments, e.g. for trap-assisted nuclear decay spectroscopy. This contribution focuses on these two possible applications with the presentation of some recent results on superallowed beta decays.
First mass measurement at JYFLTRAP
2004
The first mass measurements at JYFLTRAP facility are reviewed. Those are also first ever direct mass measurements of the heaviest Zr-isotopes. Results are compared to atomic mass evaluation data and the recent calculations. The first TOF-resonances from high-precision trap and an implication to high-precision mass measurements are discussed.
Towards high-accuracy mass spectrometry of highly charged short-lived ions at ISOLTRAP
2006
Dedicated to H.-J. Kluge on the occasion of his 65th birthday anniversary - Jürgen Kluge Special Issue; Multiply charged ions of stable xenon isotopes from a plasma ion source have been mass-selected by the on-line mass separator ISOLDE/CERN and delivered to the triple-trap mass spectrometer ISOLTRAP. The doubly charged ions that survived the charge-exchange processes during bunching and ion preparation were transferred to a precision Penning trap for mass determination. Mass values were obtained for the isotopes with mass numbers A=126,129,130,136. They are consistent with previous results except for the case of $^{126}Xe$ where a significant deviation from the literature value was found. …
Local Structure Studies of Ti for SrTi16O3 and SrTi18O3 by Advanced X-ray Absorption Spectroscopy Data Analysis
2015
Strontium titanate is a model quantum paraelectric in which in the region of dominating quantum statistics the ferroelectric instability is inhibited due to nearly complete compensation of the harmonic contribution into ferroelectric soft mode frequency by the zero-point motion contribution. The enhancement of atomic masses by the substitution of 18O for 16O decreases the zero-point atomic motion and low-T ferroelectricity in SrTi18O3 is realized. In this study we report on the local structure of Ti in SrTi16O3 and SrTi18O3 by Ti K-edge extended x-ray absorption fine structure measurements in temperature range 6 – 300 K.
Mass Spectroscopy in Penning Trap
2009
While mass spectrometry in Paul traps serves well mainly for molecular analysis in chemistry, Penning traps provide high accuracy and precision. The technique is based on the fact that the ratio of cyclotron frequencies ω c = (Q/M)B of two ions in the same magnetic field B gives directly the ratio of their masses ω c(1)/ω c(2) = M(2)/M(1). If carbon-12 as the standard of the atomic mass scale is used as reference, the mass of the ion of interest is obtained directly in atomic units. Although the cyclotron frequency is not an eigenfrequency of the Penning trap, it can be obtained from combinations of ω+, ω, and ω z as evident from the set of equations (1.31)-(1.33). In the ideal case of a pe…
Direct mass measurements on neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer
2002
The masses of Xe isotopes with 124 A 114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500000 was chosen resulting in an accuracy of m 12 keV for all isotopes investigated. Con icts with existing mass data of several standard deviations were found. peerReviewed
Mass measurements of As, Se, and Br nuclei, and their implication on the proton-neutron interaction strength toward the N=Z line
2021
Mass measurements of the $^{69}$As, $^{70,71}$Se and $^{71}$Br isotopes, produced via fragmentation of a $^{124}$Xe primary beam at the FRS at GSI, have been performed with the multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) of the FRS Ion Catcher with an unprecedented mass resolving power of almost 1,000,000. For the $^{69}$As isotope, this is the first direct mass measurement. A mass uncertainty of 22 keV was achieved with only 10 events. For the $^{70}$Se isotope, a mass uncertainty of 2.6 keV was obtained, corresponding to a relative accuracy of $\delta$m/m = 4.0$\times 10^{-8}$, with less than 500 events. The masses of the $^{71}$Se and $^{71}$Br isotopes were measured…