[en] A system to determine the density and temperature of ground state hydrogen atoms in a plasma by vacuum ultraviolet laser absorption spectroscopy is described. The continuous tunability of the spectrometer allows for analysis at any of the Lyman transitions. The narrow bandwidth of the laser system allows for the accurate determination of the absorption lineshape and hence the translational temperature. The utility of the system is exemplified by data obtained on an ion-source plasma. The measurements demonstrate the quality of the data as well as illustrating the behavior of this ion source under varying discharge conditions. 9 refs., 5 figs., 1 tab

[en] A 100-mA, 2.07-MeV Radio-Frequency Quadrupole (RFQ III) has been commissioned and operated routinely on the Accelerator Test Stand (ATS) [1] at Los Alamos National Laboratory. To characterize the RFQ output beam dynamics, measurements were made of the beam transmission and of the transverse and longitudinal phase-space distributions. Data were taken for different RFQ III operating conditions and compared to simulations

[en] A detailed comparison of theory and experiment concerning the longitudinal beam dynamics of a 2- to 5- MeV drift-tube linac (DTL) was carried out. Beam output energy and phase were measured as a function of DTL rf field amplitude and phase. Comparison between experimental data and theory was found to be in good agreement. 1 ref., 9 figs

[en] A 100-mA, 2.07-MeV Radio-Frequency Quadrupole (RFQ III) has been commissioned and operated routinely on the Accelerator Test Stand (ATS) at Los Alamos National Laboratory. To characterize the RFQ output beam dynamics, measurements were made of the beam transmission and of the transverse and longitudinal phase-space distributions. Data were taken for different RFQ III operating conditions and compared to simulations

[en] A system to determine the density and temperature of ground-state hydrogen atoms in a plasma by vacuum ultraviolet laser-absorption spectroscopy is described. The continuous tunability of the spectrometer allows for analysis at any of the Lyman transitions. The narrow bandwidth of the laser source allows for the accurate determination of the hydrogen absorption line shape and, hence, the translational temperature. The utility of the system is exemplified by data obtained on an ion source plasma. The measurements show the quality of the data as well as illustrating the behavior of these sources under varying discharge conditions

[en] A system to determine the density and temperature of ground-state hydrogen atoms in a hydrogen plasma by measurement of the absorption of Lyman-beta or Lyman-gamma radiation is described. The Lyman-series radiation is generated by resonant four-wave sum-frequency mixing in mercury vapor. A wide range of hydrogen atom densities can be measured by employing these two transitions. A sample measurement on a H^- ion-source discharge is presented. Extensions to Lyman-alpha and other vacuum-ultraviolet wavelengths are discussed

[en] The parameters for the proposed Superconducting Super Collider (SSC) linac injector system are obtained from the established requirements of the low-energy booster (LEB). The first element of this injector system is a radio frequency quadrupole (RFQ) that bunches the H^- ions and accelerates these ion bunches to 2.5 MeV. With a suitable matching section, this beam is injected into a drift-tube linac (DTL), which takes the ions to 120 MeV. The final element is a coupled-cavity linac (CCL) designed to accelerate the H^- ions to 600 MeV for injection into the LEB. In this paper the conceptual beam dynamics design for the various elements of this linac injection system is described

[en] A new technique, vacuum ultraviolet laser absorption spectroscopy, has been developed to quantitatively determine the absolute density of H and H₂ within a plasma. The technique is particularly well suited to measurement in a plasma, where high charged particle and photon backgrounds complicate other methods of detection. The high selectivity and sensitivity of the technique allows for the measurement of the rotational-vibrational state distribution of H₂ as well as the translational temperature of the atoms and molecules. The technique has been used to study both pulsed and continuous plasma discharges. H₂ state distributions show a high degree of internal excitation, with levels up to v=5 and J=8 being observed. Hydrogen atom measurements indicate that, even for modest discharge currents, the fraction of H₂ molecules dissociated can be greater than 0.15

[en] We recently reported the H⁰ density and temperature in the 4X source (a Penning SPS) as a function of the H₂ gas flow and the discharge current, as well as a measurement of the H₂ (v=1) vibrational state density. In this paper, we report the H⁰ density and temperature in the 4X source as a function of magnetic field for the same source geometry of the previous report and as a function of H₂ gas flow and discharge current for a smaller discharge chamber. When the smaller discharge chamber is used, the plasma column H⁰ density increases from 7x10¹⁴ cm^-3 to 8x10¹⁴ cm^-3 and the plasma column H⁰ temperature increases from 1.5 to 1.9 eV

[en] Using vacuum ultraviolet laser-absorption spectroscopy, the H⁰ density and temperature are measured as a function of discharge current and H₂-gas flow in both the plasma column and the drift region between the plasma column and the emitter in the 4X source. For typical source operating parameters, the atom temperature is 1.5 eV in the plasma column and 0.6 eV in the drift region; the atom density 7x10¹⁴ cm^-3 in the plasma column and 4x10¹⁴ cm^-3 in the drift region. Separate measurements give 2% for the ratio of H₂ molecules in the first vibrational level to the total H₂ density