Equilibrium charge-state fractions of 3.3-39 keV deuterium atoms and ions in magnesium vapor are reported. The maximum D− yield is 6.2% at low energies.

Total collision cross-section measurements of 1.25- to 25-keV ${\mathrm{H}}^{+}$, ${\mathrm{H}}^{0}$, ${\mathrm{H}}^{\ensuremath{-}}$ and $\mathrm{H}_{2}^{}{}_{}{}^{+}$ in Xe are reported for the nine processes ${\mathrm{H}}^{+}$ \ensuremath{\leftrightarrows} ${\mathrm{H}}^{0}$, ${\mathrm{H}}^{+}$ \ensuremath{\leftrightarrows} ${\mathrm{H}}^{\ensuremath{-}}$, ${\mathrm{H}}^{0}$ \ensuremath{\leftrightarrows} ${\mathrm{H}}^{\ensuremath{-}}$, and $\mathrm{H}_{2}^{}{}_{}{}^{+}$ \ensuremath{\rightarrow} [${\mathrm{H}}^{+}$, ${\mathrm{H}}^{\ensuremath{-}}$, ($\mathrm{H}_{2}^{}{}_{}{}^{0}$ and ${\mathrm{H}}^{0}$)]. Single- and double-electron-stripping cross sections for which the Xe atom does not change charge are deduced by combining present and past results. Comparisons are made with available experimental data and with theoretical values.

Cross-section measurements of the dissociation modes $\mathrm{H}_{3}^{}{}_{}{}^{+}$ \ensuremath{\rightarrow} (3H and H + ${\mathrm{H}}_{2}$), H + $\mathrm{H}_{2}^{}{}_{}{}^{+}$, ${\mathrm{H}}^{+}$ + 2H, ${\mathrm{H}}^{+}$ + ${\mathrm{H}}_{2}$, H + 2${\mathrm{H}}^{+}$, ${\mathrm{H}}^{+}$ + $\mathrm{H}_{2}^{}{}_{}{}^{+}$, and 3${\mathrm{H}}^{+}$ are reported for $\mathrm{H}_{3}^{}{}_{}{}^{+}$ energies between 400 and 1800 keV in targets of ${\mathrm{H}}_{2}$, ${\mathrm{N}}_{2}$, and Li. For the ${\mathrm{H}}_{2}$ target, comparisons are made with available previous measurements of H, ${\mathrm{H}}^{+}$, ${\mathrm{H}}_{2}$, and $\mathrm{H}_{2}^{}{}_{}{}^{+}$ production cross sections at lower energies. Cross-section measurements for 270- to 1200-keV ${\mathrm{H}}_{2}$ \ensuremath{\rightarrow} $\mathrm{H}_{2}^{}{}_{}{}^{+}$, H + ${\mathrm{H}}^{+}$, and 2${\mathrm{H}}^{+}$ are also reported.

Cross-section measurements of the dissociation modes H/sub 3//sup +/ yields (3H and H + H/sub 2/), H + H/sub 2/sup +/ + 2H, H/sup +/ + H/sub 2/, H + 2H/sup +/, H/ sup +/ + H/sub 2//sup +/, and 3H/sup +/ are reported for H/sub 3// sup +/ energies between 400 and 1800 keV in targets of H/sub 2/, N/sub 2/, and Li. For the H/sub 2/ target, compariso ns are made with available previous measurements of H, H/sup +/, H/sub 2/, and H/sub 2/ /sup +/ production cross sections at lower energies. Cross-section measurements for 270- to 1200-keV H/ sub 2/ yields H/sub 2//sup +/, H + H/sup +/, and 2H/sup +/ a re also reported. (auth)

We describe a neutral beam source capable of producing pulsed deuterium beams of up to 15 A equivalent current at 20 keV for heating and sustaining fusion plasmas. It consists of a large-area plasma source, multiple-aperture accel-decel extractor, and closely coupled charge-exchange cell. A larger source, to produce 80 A equivalent deuterium beams at 20 keV, is being constructed.

Experimental yields of neutral ground-state atoms and molecules and long-lived 3?u excited molecules from interactions of 30- to 120-keV ions in magnesium vapour are reported. Results of calculations that approximate trapping in magnetically confined plasmas of beams produced by either D+ or ions neutralized in Mg-vapour are given.

Charge-state fractions and yields of highly excited deuterium atoms produced by electron capture when 8-100-keV deuterons emerge from C, Mg, Nb, and Au surfaces deposited on thin carbon foils under high-vacuum conditions are reported. Atoms with principal quantum number $n=6$ were detected with an optical technique; atoms in the levels $n\ensuremath{\approx}12 \mathrm{to} 18$ were detected by ionizing them in a strong electric field. Changes with time after evaporation, presumably due to contamination of the surfaces, were observed. The experimental results are compared with available theoretical estimates. Solid and vapor targets are compared for Mg.

The gas collisional cross sections for breakup of 20.9-MeV ${\mathrm{H}}_{2}^{+}$ ions into ${\mathrm{H}}^{0}$+${\mathrm{H}}^{+}$ and ${\mathrm{H}}^{+}$+${\mathrm{H}}^{+}$+$e$ have been measured in ${\mathrm{H}}_{2}$, He, ${\mathrm{N}}_{2}$, and Ar. Total dissociation cross sections in the same gases and in the energy range 10 to 65 MeV have been deduced from radial-attenuation measurements on the internal beam of the Berkeley 88-in. cyclotron. These cross sections have also been calculated for each of the ${\mathrm{H}}_{2}^{+}$ molecular-ion vibrational levels and for an average over the vibrational levels, with an approach proposed by Salpeter. The measured and calculated average cross sections are in good agreement.

Cross sections for collisional electron detachment from 20-MeV deuterium atoms and negative ions have been measured in ${\mathrm{H}}_{2}$, He, ${\mathrm{N}}_{2}$, and Ar. The cross sections ${\ensuremath{\sigma}}_{01}$ per target molecule for the ionization of neutral atoms are 2.2, 1.6, 20, and 36, respectively, in units of ${10}^{\ensuremath{-}18}$ ${\mathrm{cm}}^{2}$. Results for single-electron detachment from ${\mathrm{D}}^{\ensuremath{-}}$ ions, ${\ensuremath{\sigma}}_{\ensuremath{-}10}$, are 7.5, 4.7, 58, and 75, respectively. All values have an uncertainty of \ifmmode\pm\else\textpm\fi{}10%, chiefly from absolute-pressure calibration uncertainties. The experimental values for atoms in ${\mathrm{H}}_{2}$ and He are in agreement with calculations that use the Born and free-collision approximations. The measured cross sections for single-electron detachment from negative ions in ${\mathrm{H}}_{2}$ and He are about one-half of the calculated values. The two-electron detachment cross sections, ${\ensuremath{\sigma}}_{\ensuremath{-}11}$, are approximately 4% of the single-detachment cross sections, ${\ensuremath{\sigma}}_{\ensuremath{-}10}$, in all gases.