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in creator/contributor: "Lykke, K."

open access

Plasma modified production of high-current, high-purity cw H{sup +}, D{sup +}, and H{sup -} beams from microwave-driven sources

We have recently reported production of cw proton beams from magnetically confined microwave-driven sources, operating under nonresonant (non-ECR) conditions, with proton fractions > 0.95, the remaining fraction consisting of H{sub 2}{sup +} (0.05) with no H{sub 3}{sup +}. We achieve this by adding H{sub 2}O to the plasma at molecular concentrations of 1% and about 700 W 2.45 GHz RF power to the source. High-current (45 mA) high-power (45 kV) beams of >92% proton purity have been produced using… more

Date: October 1996

Creator: Spence, D.; Lykke, K. R. & McMichael, G. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Molecular surface analysis by laser ionization of desorbed molecules

While elemental analysis of surfaces has progressed dramatically over the past ten years, quantitative molecular surface analysis remains difficult. This is particularly true in the analysis of complex materials such as polymers and rubbers which contain a wide compliment of additives and pigments to enhance their material characteristics. For mass spectrometric analysis the difficulty is two fold. First, desorption of surface molecules must be accompanied with minimal fragmentation and collate… more

Date: July 1, 1992

Creator: Pellin, M. J.; Lykke, K. R.; Wurz, P. & Parker, D. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Improved method for the production of atomic ion species from plasma ion sources

A technique to enhance the yield of neutral atomic and ionic species (H{sup +}, D{sup +}, O{sup +}, N{sup +}, etc.) from plasmas. The technique involves the addition of catalyzing agents to the ion discharge. Effective catalysts include H{sub 2}O, O{sub 2}, and SF{sub 6}, among others, with the most effective being water (H{sub 2}O). This technique has been developed at Argonne National Laboratory, where microwave produced beams consisting essentially of 100% atomic neutral species (H) have bee… more

Date: December 31, 1996

Creator: Spence, D. & Lykke, K.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

open access

Molecular surface analysis by laser ionization of desorbed molecules

Date: January 1, 1992

Creator: Pellin, M. J.; Lykke, K. R.; Wurz, P. & Parker, D. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Comparing TOF-SIMS with laser desorption/photoionization for surface analysis

TOF-SIMS has become the standard mass spectrometric tool for the molecular analysis of polymeric, organic, and biological surfaces. However, variations in desorption yields, ionization efficiencies, and ion-induced damage of adsorbates still present significant difficulties in the analysis of TOF-SIMS data. Laser desorption combined with photoionization may provide a significant improvement over TOF-SIMS. An instrument exists that has the capability of utilizing both methods of analysis and the… more

Date: June 1996

Creator: Trevor, J. L.; Hanley, L.; Pellin, M. J. & Lykke, K. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Production of high-brightness CW proton beams with very high proton fractions

This paper demonstrates a new technique to significantly enhance the proton fraction of an ion beam extracted from a plasma ion source. We employ a magnetically confined microwave driven source, though the technique is not source-specific and can probably be applied equally effectively to other plasma sources such as Penning and multicusp types. Specifically, we dope the plasma with about 1% H{sub 2}O, which increases the proton fraction of a 45 keV 45 mA beam from 75 to 90% with 375W 2.45 GHz … more

Date: December 1, 1995

Creator: Spence, D.; McMichael, G.; Lykke, K. R.; Schneider, J. D.; Sherman, J.; Stevens, R., Jr. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

State-to-state inelastic and reactive molecular beam scattering from surfaces

Resonantly enhanced multiphoton ionization (REMPI) laser spectroscopic and molecular beam-surface scattering techniques are coupled to study inelastic and reactive gas-surface scattering with state-to-state specificity. Rotational, vibrational, translational and angular distributions have been measured for the inelastic scattering of HCI and N {sub 2} from Au(111). In both cases the scattering is direct-inelastic in nature and exhibits interesting dynamical features such as rotational rainbow s… more

Date: January 1, 1990

Creator: Lykke, K.R. (Argonne National Lab., IL (USA)) & Kay, B.D. (Sandia National Labs., Albuquerque, NM (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A mass spectrometric analysis of {gamma}-GPS films

{gamma}-glycidoxypropyltrimethoxysilane ({gamma}-GPS) is used for pre-treatment of grit-blasted aluminum before adhesive bonding. This paper discusses analysis of non-reflective grit-blasted surfaces using mass spectrometry of species that were either sputtered off using an ion beam or thermally desorbed as neutrals using a pulsed laser and then post-ionized using a secondary laser. Results show that fragmentation is excessive and structural information is difficult to obtain from the spectra.

Date: June 1, 1996

Creator: Dillingham, R. G.; Boerio, F. J.; Bertelsen, C.; Savina, M. R.; Lykke, K. R. & Calaway, W. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Trace surface analysis using ion and photon desorption with resonance ionization detection

Surface Analysis by Resonant Ionization of Sputtered Atoms (SARISA) has demonstrated the ability to detect trace elements at concentrations below 100 ppt. Use of energetic primary ions to desorb surface species is uniquely suited for elemental surface analysis because the ratio between the number of incident energetic ions and the number of ejected surface atoms is easily quantifiable as the sputter yield. Molecular surface analysis by ion desorption does not possess this advantage, however. In… more

Date: January 1, 1991

Creator: Pellin, M. J.; Young, C. E.; Calaway, W. F.; Lykke, K. R.; Wurz, P.; Gruen, D. M. (Argonne National Lab., IL (USA)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department