A critical compilation of experimental data on spectral lines and energy levels of hydrogen, deuterium, and tritium

Kramida, Alexander

doi:10.1016/j.adt.2010.05.001

Cited by 82 publications

(58 citation statements)

References 197 publications

(651 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(7.1)) and ν 3/2 (Eq. (7.2)) are used to determine the fine structure splitting ∆ν [4,[43][44][45]. With a difference of -0.6 (2.8) kHz, our experimental result is in excellent agreement with the theoretical value and represents the most accurate optical determination of a fine structure splitting in atomic hydrogen.…”

Section: P Fine Structure Intervalsupporting

confidence: 75%

The Rydberg constant and proton size from atomic hydrogen

Beyer

Maisenbacher

Matveev

et al. 2017

Science

383

427

View full text Add to dashboard Cite

ZusammenfassungDas Wasserstoffatom (H) stellt ein einzigartiges System für Tests der Quanten-Elektrodynamik dar. Aufgrund seiner einfachen Struktur und genauen theoretischen Beschreibung liefert es außerdem wichtige Daten für die Bestimmung der RydbergKonstante R ∞ und des Proton-Ladungsradius r p im Rahmen der globalen Anpassung fundamentaler Konstanten durch das Committee on Data for Science and Technology (CODATA). Im Jahre 2010 kam das sogenannte "proton size puzzle" auf, eine Diskrepanz von sieben Standardabweichungen zwischen CODATA und dem zehn mal genauer gemessenen Wert von r p in myonischem Wasserstoff (µ -p, [1, 2] AbstractThe hydrogen atom (H) is a unique system for tests of quantum electrodynamics (QED). Due to its simplicity and accurate theoretical description, it also provides key input data for the determination of the Rydberg constant R ∞ and the proton root mean square (r.m.s.) charge radius r p in the global adjustment of fundamental constants [4] by the Committee on Data for Science and Technology (CODATA). In the year 2010, the "proton size puzzle" emerged, which refers to a discrepancy of seven standard deviations between CODATA and a ten times more accurate measurement of r p in muonic hydrogen (µ -p, [1, 2]). Proposed solutions for this puzzle cover a wide range of scenarios, up to physics beyond the standard model [3]. This thesis reports on a novel scheme for high resolution spectroscopy of dipole allowed 2S -nP transitions in H, using a cryogenic beam of H atoms that are prepared in the meta-stable 2S F =0 1/2 state by state selective optical excitation. Such measurements can be used for a new determination of R ∞ and r p from H spectroscopy, shedding new light on the "proton size puzzle". The scheme has been applied to spectroscopy of the 2S-4P transition first, yielding: These values are as accurate as the ones determined from the aggregate world data of precision H spectroscopy (15 measurements) that enter the CODATA adjustment. While a discrepancy of 3.8 combined standard deviations is found to the latter, the presented results agree with the measurements in µ -p. The 2S-4P experiment is essentially unaffected by the systematic effects dominating the uncertainties in the previous most precise determinations of R ∞ using dipole forbidden two photon transitions in H. Instead, the main systematic effects are the first order Doppler effect, canceled by the use of an active fiber-based retroreflector (AFR) developed in this thesis, and line shape distortions due to quantum interference (QI) of neighboring atomic resonances. The latter effect has come to the attention of the precision spectroscopy community only recently [8,9]. Apparent QI line shifts have been studied experimentally, yielding the first direct observation in precision spectroscopy of largely separated atomic resonances. The observed shifts of up to ± 51 kHz are six times larger than the proton size discrepancy for the 2S-4P transition. They are brought under control by a suitable line shape model function, derived and...

show abstract

Section: P Fine Structure Intervalsupporting

confidence: 75%

The Rydberg constant and proton size from atomic hydrogen

Beyer

Maisenbacher

Matveev

et al. 2017

Science

383

427

View full text Add to dashboard Cite

show abstract

“…Parameters of the H-He molecular potentials are given in Tables 1 and 2. Figure 7 shows the dependence on R of the radiative transition moments between the excited states and the perturbations of those states as the H and He atoms approach from large R. Kramida (2010).…”

Section: Appendixmentioning

confidence: 99%

H–He collision-induced satellite in the Lyman α profile of DBA white dwarf stars

Allard

Kielkopf

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The spectra of helium-dominated white dwarf stars with hydrogen in their atmosphere present a distinctive broad feature centered around 1160Å in the blue wing of the Lyman-α line. It is extremely apparent in WD 1425+540 recently observed with HST COS. With new theoretical line profiles based on ab initio atomic interaction potentials we show that this feature is a signature of a collision-induced satellite due to an asymptotically forbidden transition. This quasi-molecular spectral satellite is crucial to understanding the asymmetrical shape of Lyman-α seen in this and other white dwarf spectra. Our previous work predicting this absorption feature was limited by molecular potentials that were not adequate to follow the atomic interactions with spectroscopic precision to the asymptotic limit of large separation. A new set of potential energy curves and electronic dipole transition moments for the lowest electronic states of the H-He system were developed to account accurately for the behaviour of the atomic interactions at all distances, from the chemical regime within 1Å out to where the radiating H atoms are not significantly perturbed by their neighbors. We use a general unified theory of collision-broadened atomic spectral lines to describe a rigorous treatment of hydrogen Lyman-α with these potentials and present a new study of its broadening by radiative collisions of hydrogen and neutral helium. These results enable ab initio modeling of radiative transport in DBA white dwarf atmospheres.

show abstract

“…We simulate the longer-wavelength Lyman-series line absorption from a list of transition wavelengths and oscillator strengths from the NIST atomic database 13 (Kramida 2010). We adopted a Gaussianshaped Doppler broadening of 1 km s −1 to accompany the Lorentzian natural linewidths of the H lines in the simulated photoabsorption cross section.…”

Section: H -Hydrogenmentioning

confidence: 99%

Photodissociation and photoionisation of atoms and molecules of astrophysical interest

Heays

Bosman

Dishoeck

2017

A&A

442

View full text Add to dashboard Cite

A new collection of photodissociation and photoionisation cross sections for 102 atoms and molecules of astrochemical interest has been assembled, along with a brief review of the basic physical processes involved. These have been used to calculate dissociation and ionisation rates, with uncertainties, in a standard ultraviolet interstellar radiation field (ISRF) and for other wavelength-dependent radiation fields, including cool stellar and solar radiation, Lyman-α dominated radiation, and a cosmic-ray induced ultraviolet flux. The new ISRF rates generally agree within 30% with our previous compilations, with a few notable exceptions. Comparison with other databases such as PHIDRATES is made. The reduction of rates in shielded regions was calculated as a function of dust, molecular and atomic hydrogen, atomic C, and self-shielding column densities. The relative importance of these shielding types depends on the atom or molecule in question and the assumed dust optical properties. All of the new data are publicly available from the Leiden photodissociation and ionisation database. Sensitivity of the calculated rates to variation of temperature and isotope, and uncertainties in measured or calculated cross sections, are tested and discussed. Tests were conducted on the new rates with an interstellar-cloud chemical model, and find general agreement (within a factor of two) in abundances obtained with the previous iteration of the Leiden database assuming an ISRF, and order-of-magnitude variations assuming various kinds of stellar radiation. The newly parameterised dust-shielding factors makes a factor-of-two difference to many atomic and molecular abundances relative to parameters currently in the UDfA and KIDA astrochemical reaction databases. The newly-calculated cosmic-ray induced photodissociation and ionisation rates differ from current standard values up to a factor of 5. Under high temperature and cosmic-ray-flux conditions the new rates alter the equilibrium abundances of abundant dark cloud abundances by up to a factor of two. The partial cross sections for H 2 O and NH 3 photodissociation forming OH, O, NH 2 and NH are also evaluated and lead to radiation-field-dependent branching ratios.

show abstract

A critical compilation of experimental data on spectral lines and energy levels of hydrogen, deuterium, and tritium

Cited by 82 publications

References 197 publications

The Rydberg constant and proton size from atomic hydrogen

The Rydberg constant and proton size from atomic hydrogen

H–He collision-induced satellite in the Lyman α profile of DBA white dwarf stars

Photodissociation and photoionisation of atoms and molecules of astrophysical interest

Contact Info

Product

Resources

About