TY - JOUR

T1 - On the Mechanisms of Formation of Excited Hydrogen Atoms in a Decaying Helium-Hydrogen Plasma

AU - Skoblo, Yu É

AU - Ivanov, V. A.

PY - 2003/10

Y1 - 2003/10

N2 - We spectroscopically studied the population of the excited hydrogen atomic states with the principal quantum numbers n = 3 and 4 in a decaying plasma produced by a pulsed discharge in a mixture of helium (p = 40.4 Torr) with a small amount of hydrogen ([H2] ≈ 1012 cm-3). Experiments on recording the response of the spectral line intensities to a short-duration electron temperature perturbation revealed the contribution of electron-ion recombination to the population of the H*(n = 3) states in the early afterglow. The ions produced by collisions of hydrogen molecules with metastable He(23S1) atoms, whose density decreases relatively rapidly with time in the decaying plasma, were assumed to be involved in this process. No population of the H*(n = 4) atomic levels due to electron-ion recombination was found. Our experimental results are consistent with the conclusions of previous studies that excitation transfer during collisions of metastable helium molecules with hydrogen molecules plays a major role in the population of the excited hydrogen atomic states both with n = 3 and with n = 4 during most of the afterglow.

AB - We spectroscopically studied the population of the excited hydrogen atomic states with the principal quantum numbers n = 3 and 4 in a decaying plasma produced by a pulsed discharge in a mixture of helium (p = 40.4 Torr) with a small amount of hydrogen ([H2] ≈ 1012 cm-3). Experiments on recording the response of the spectral line intensities to a short-duration electron temperature perturbation revealed the contribution of electron-ion recombination to the population of the H*(n = 3) states in the early afterglow. The ions produced by collisions of hydrogen molecules with metastable He(23S1) atoms, whose density decreases relatively rapidly with time in the decaying plasma, were assumed to be involved in this process. No population of the H*(n = 4) atomic levels due to electron-ion recombination was found. Our experimental results are consistent with the conclusions of previous studies that excitation transfer during collisions of metastable helium molecules with hydrogen molecules plays a major role in the population of the excited hydrogen atomic states both with n = 3 and with n = 4 during most of the afterglow.

UR - http://www.scopus.com/inward/record.url?scp=0346948448&partnerID=8YFLogxK

U2 - 10.1134/1.1621432

DO - 10.1134/1.1621432

M3 - Article

AN - SCOPUS:0346948448

VL - 95

SP - 507

EP - 510

JO - OPTICS AND SPECTROSCOPY

JF - OPTICS AND SPECTROSCOPY

SN - 0030-400X

IS - 4

ER -