Video Experimental Relacionado

Updated: Jul 12, 2026

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Published on: March 29, 2016

Tasa de destrucción de h3+ por electrones de baja energía medida en un experimento de anillo de almacenamiento

G Sundström, J R Mowat, H Danared

Science (New York, N.Y.)

|February 11, 1994

Resumen

Las mediciones precisas de la tasa de destrucción del catión trihidrógeno (H3+) son cruciales para comprender las atmósferas interestelares y planetarias. Este estudio proporciona un coeficiente de velocidad preciso para la recombinación disociativa de H3+ con electrones, resolviendo las incertidumbres anteriores.

Área de la Ciencia:

La astroquímica es astroquímica.
Física del plasma es la física del plasma.
Ciencias de la atmósfera Ciencias atmosféricas.

Sus antecedentes:

La abundancia de cationes de trihidrógeno (H3+) es crítica para la química atmosférica interestelar y planetaria.
La disociación por impacto de electrones de baja energía es una vía primaria de destrucción de H3+, pero las estimaciones de la velocidad de reacción varían significativamente.

Objetivo del estudio:

Para resolver las incertidumbres en el coeficiente de tasa de recombinación disociativa H3+.
Para medir la sección transversal de H3+ vibracionalmente frío con electrones de baja energía.

Principales métodos:

Utilizó un anillo de almacenamiento de iones para medir la sección transversal de recombinación disociativa.
Se realizaron mediciones hasta energías de colisión por debajo de 1 milielectronvolt.

Principales resultados:

Se determinó un coeficiente de velocidad de 1,15 x 10(-7) cm3/s a 300 K.
Se observó una dependencia de la energía de colisión de E(-1.15) para la sección transversal.
Dedujo una dependencia de temperatura de T ((-0.65) para la tasa.

Conclusiones:

Proporciona un coeficiente preciso de la tasa de recombinación disociativa H3+, resolviendo las discrepancias anteriores.
La dependencia de temperatura determinada es vital para el modelado preciso de las atmósferas interestelares y planetarias.

Más Videos Relacionados

Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh

Preparing an Isotopically Pure ²²⁹Th Ion Beam for Studies of ^229mTh

Published on: May 3, 2019

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C₂, CN, and TiO Spectra Following Laser-induced Optical Breakdown

Published on: February 14, 2014

Videos de Conceptos Relacionados

Atomic Nuclei: Nuclear Spin State Population Distribution

Atomic Nuclei: Nuclear Spin State Population Distribution

Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.

Thomson's e/m Experiment

Thomson's e/m Experiment

In a beam of charged particles created by a heated cathode, the particles move at different speeds. However, many applications need a beam with uniform particle speeds. An arrangement known as a velocity selector uses electric and magnetic fields to pick particles with a particular speed from the beam.
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...

¹H NMR of Labile Protons: Deuterium (²H) Substitution

¹H NMR of Labile Protons: Deuterium (²H) Substitution

This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.

¹³C NMR: ¹H–¹³C Decoupling

¹³C NMR: ¹H–¹³C Decoupling

The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...

Nuclear Binding Energy

Nuclear Binding Energy

The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect indicates a “loss” in mass of 4.0331 amu – 4.0026 amu = 0.0305 amu. The loss in mass accompanying the formation of an atom from protons, neutrons, and electrons is due to the conversion of that mass into energy that is evolved as the atom forms. The nuclear binding energy is the energy produced when the atoms’ nucleons are bound together;...