Search results for "Ionization Energy"
showing 10 items of 83 documents
Rydberg Series Excitation of a Single Trapped Ca+40 Ion for Precision Measurements and Principal Quantum Number Scalings
2021
A complete set of spectroscopic data is indispensable when using Rydberg states of trapped ions for quantum information processing. We carried out Rydberg series spectroscopy for $n{S}_{1/2}$ states with $38\ensuremath{\le}n\ensuremath{\le}65$ and for $n{D}_{5/2}$ states with $37\ensuremath{\le}n\ensuremath{\le}50$ on a single trapped $^{40}{\mathrm{Ca}}^{+}$ ion. We determined the ionization energy of 2 870 575.582(15) GHz, 60 times more accurately as compared to the accepted value and contradicting it by 7.5 standard deviations. We confirm quantum defect values of ${\ensuremath{\delta}}_{{S}_{1/2}}=1.802\text{ }995(5)$ and ${\ensuremath{\delta}}_{{D}_{5/2}}=0.626\text{ }888(9)$ for $n{S}_…
How can the nucleus be lighter than its constituents?
2021
Abstract The fact that the nucleus is lighter than its constituents, seems rather strange. How can the whole have a smaller mass than its components? To get some intuition about how this is possible, one can look at a simpler more familiar system exhibiting the same phenomena; the hydrogen atom. It turns out that the same is true here; the hydrogen atom is a little bit lighter than the sum of its constituents. This difference corresponds to the ionisation energy of hydrogen. This observation allows a simple explanation for how this is possible; the destructive interference between the electric fields of the proton and electron causes a reduction in the energy of the electric field and hence…
Ionization potential of Al6 and A17 as a function of temperature
1999
The temperature-depence of the ionization potential of Al6 and Al7 clusters is studied by using ab initio molecular dynamics. The threshold regions of theoretical photoionization eciency curves are ob- tained from the calculated ionization potential distributions by integration and the determined ionization potentials are compared with the experimental ones. Two important eects, which complicate the determin- ation of ionization potential from photoionization eciency curves, are observed: the thermal tail eect and the isomerization. Also a link between the adiabatic ionization potential and the threshold of the photoion- ization eciency curve is discussed. In the case of Al7, this often use…
Three-step resonant photoionization spectroscopy of Ni and Ge: ionization potential and odd-parity Rydberg levels
2007
In preparation of a laser ion source, we have investigated multi-step laser ionization via Rydberg and autoionizing states for atomic Ni and Ge using a mass separator with an ion beam energy of 20 keV. For both elements resonant three-step excitation schemes suitable for modern Ti:sapphire laser systems were developed. Rydberg series in the range of principal quantum numbers 20 n 80 were localized, assigned and quantum numbers were allocated to the individual resonances. Ionization potentials (IP) were extracted from fits of the individual series and quantum defects of individual levels were analysed for confirmation of series assignment. For Ni the ionization potential could be extracted w…
Investigation of nitrogen-related acceptor centers in indium selenide by means of photoluminescence: Determination of the hole effective mass
1997
In this work we report on steady-state and time-resolved photoluminescence (PL) measurements in nitrogen-doped p-type indium selenide in the 33--210-K temperature range. In samples with low nitrogen concentration the photoluminescence spectrum consists of exciton-related peaks and a band-to-acceptor recombination peak (2.1-\ensuremath{\mu}s lifetime) with LO-phonon replica. An ionization energy of 65.5 meV is proposed for the nitrogen-related acceptor. A long-lived (18 \ensuremath{\mu}s) component, which consists of an asymmetric broadband centered around the acceptor peak, has been also detected by means of time-resolved PL. Samples with a higher nitrogen concentration show a PL spectrum t…
First ionization potential of the heaviest actinide lawrencium, element 103
2016
The first ionization potential (IP1 ) of element 103, lawrencium (Lr), has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP 1 value is 4.9630.08 0.07 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15) eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s 2 5f 14 7p 1 1/2 , which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens t…
Determination of quantum defect for the Rydberg P series of Ca II
2019
We present an experimental investigation of the Rydberg 23 P$_{1/2}$ state of laser-cooled $^{40}$Ca$^+$ ions in a radiofrequency ion trap. Using micromotion sideband spectroscopy on a narrow quadrupole transition, the oscillating electric field at the ion position was precisely characterised, and the modulation of the Rydberg transition due to this field was minimised. From a correlated fit to this P line and previously measured P and F level energies of Ca II, we have determined the ionization energy of 95 751.916(32) $\rm {cm}^{-1}$, in agreement with the accepted value, and the quantum defect for the $n$ P$_{1/2}$ states.
Electrons on a spherical surface: Physical properties and hollow spherical clusters
2012
We discuss the physical properties of a noninteracting electron gas constrained to a spherical surface. In particular we consider its chemical potentials, its ionization potential, and its electric static polarizability. All these properties are discussed analytically as functions of the number $N$ of electrons. The trends obtained with increasing $N$ are compared with those of the corresponding properties experimentally measured or theoretically evaluated for quasispherical hollow atomic and molecular clusters. Most of the properties investigated display similar trends, characterized by a prominence of shell effects. This leads to the definition of a scale-invariant distribution of magic n…
Periodic Table of the Elements, History, Education and Evaluation
2021
The periodic tables of transition metal thiophosphates MPS3, transition metal dichalcogenides MX2 and other materials, the origin of chemical elements and toxic trace elements in dried mushrooms are provided. The effective nucleus-electron attraction is proportional to the effective nuclear charge (Zeff) and inversely proportional to the effective principal quantum number (n*). The periodic arch is one of many modern visual displays that have been developed to augment the traditional periodic table of the chemical elements. The table is related to the multiparameter optimisation of N atom, nuclear magnetic resonance and everyday life. Educational activities were developed and evaluated. Se …
High‐Resolution X‐Ray Spectroscopy of the Post–T Tauri Star PZ Telescopii
2004
We present an analysis of the Chandra High Energy Transmission Grating Spectrometer observation of the rapidly rotating P_(rot)=0.94 d post T Tauri (~20 Myr old) star PZ Telescopii, in the Tucana association. Using two different methods we have derived the coronal emission measure distribution, em(T), and chemical abundances. The em(T) peaks at log T = 6.9 and exhibits a significant emission measure at temperatures log T > 7. The coronal abundances are generally ~0.5 times the solar photospheric values that are presumed fairly representative of the composition of the underlying star. A minimum in abundance is seen at a first ionization potential (FIP) of 7-8 eV, with evidence for higher abu…