An approach is described for high-throughput quality assessment of drug candidate libraries using acoustic ejection high-resolution mass spectrometry (AEMS). Sample introduction from 1536-well plates demonstrated this application 2.5 nL acoustically dispensed sample droplets into an Open Port Interface (OPI) with pneumatically assisted electrospray ionization at a rate one second per sample. Both positive and negative are shown to be essential extend the compound coverage protease...

The electron affinity of lanthanum has been measured using laser photoelectron energy spectroscopy. This is the first measurement for and one measurements an a rare-earth series element. was to be . At least bound excited state also observed in spectra, binding relative ground as present experimental are compared recent calculation.

Evidence of odd-numbered Cn2− (n=7–13) cluster beams produced in a cesium-sputter negative ion source has been observed. The minimum lifetime smallest dianion, C72−, is estimated to be at least 55 μs. An experiment investigate the structure these dianions also described.

Photoionization of Cl III ions into IV was studied theoretically using the ab initio relativistic Breit–Pauli R-matrix (BPRM) method and experimentally at Advanced Light Source (ALS) synchrotron Lawrence Berkeley National Laboratory. A relative-ion-yield spectrum measured with a photon energy resolution 10 meV. The theoretical study carried out large wave-function expansion 45 levels configurations 3s23p2, 3s3p3, 3s23p3d, 3s23p4s, 3s3p23d, 3p4. resulting spectra are complex. We have compared...

We report the first experimental determination of electron affinity gallium. The experiment was performed using laser photodetachment spectrometry technique. Photoelectron kinetic energy spectra from and were used to calibrate scale for photoelectron spectra. determined be . This measurement is compared several recent calculations

The spectral dependence of the angular distributions photoelectrons produced by single-photon detachment ${\mathrm{Al}}^{\mathrm{\ensuremath{-}}},$ ${\mathrm{Si}}^{\mathrm{\ensuremath{-}}},$ and ${\mathrm{P}}^{\mathrm{\ensuremath{-}}}$ ions has been measured at five discrete photon wavelengths ranging from 457.9 to 647.1 nm (2.71--1.92 eV) using a crossed laser-ion beam apparatus. Values asymmetry parameter have determined fits photoelectron yield as function angle between laser polarization...

Photodetachment cross sections and the angular distributions of photoelectrons produced by single-photon detachment transition metal negative ions ${\mathrm{Fe}}^{\ensuremath{-}}$ ${\mathrm{Cu}}^{\ensuremath{-}}$ have been measured at four discrete photon wavelengths ranging from 457.9 to $647.1\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ $(2.71--1.92\phantom{\rule{0.3em}{0ex}}\mathrm{eV})$ using a crossed-beams laser photodetachment electron spectrometry (LPES) apparatus. were determined...

The relative photodetachment cross section of ${\mathrm{Al}}^{\mathrm{\ensuremath{-}}}$ has been measured in the wavelength range 2420--2820 nm (0.440--0.512 eV), using a coaxial ion-laser beams apparatus, which 2.98-keV beam is merged with from an F-center laser. cross-section data near $^{3}$${\mathit{P}}_{0,1,2}$${\ensuremath{\rightarrow}}^{2}$${\mathit{P}}_{1/2,3/2}$ threshold have fitted to Wigner law and zero-core-contribution theory photodetachment. electron affinity aluminum was...

Photoelectron angular distributions for the laser photodetachment process have been measured at six wavelengths in region 457.9 - 647.1 nm. An intense 10 keV beam was produced a caesium sputter-type ion source and mass-selected with bending magnet. The subsequently crossed linearly polarized, continuous photon beam. Angular were obtained by measuring laboratory-frame energy spectra of photodetached electrons as function angle between velocity vector ejected polarization direction polarized...

The correlated process involving the photodetachment of two electrons from ${\mathrm{Cl}}^{\ensuremath{-}}$ ion has been investigated over photon energy range 20--45 eV. In experiment, a beam photons Advanced Light Source (ALS) was collinearly merged with counterpropagating ions sputter source. ${\mathrm{Cl}}^{+}$ produced in interaction region were detected, and normalized signal used to monitor relative cross section for reaction. An absolute scale established by measuring spatial overlap...

We obtain relative cross sections for the production of photoelectrons with specific angular momentum quantum numbers. These are obtained from polarization analysis visible fluorescence ions produced when circularly polarized vacuum ultraviolet radiation photoionizes ground state Ar. The ratio same orbital but different total momenta shows strong deviations statistical ratio, demonstrating importance relativistic interactions in many-electron photoionization dynamics.

Measurements of the single photoionization cross section Cu-like Zn$^+$ ions are reported in energy (wavelength) range 17.5 eV (709 \AA) to 90 (138 \AA). The measurements on this {\it trans}-Fe element were performed at Advanced Light Source synchrotron radiation facility Berkeley, California a photon resolution 17 meV using photon-ion merged-beams end-station. Below 30 spectrum is dominated by excitation autoionizing resonance states. experimental results compared with large-scale...

Photodetached $d$-electron angular distributions have been measured for the processes ${\mathrm{V}}^{\ensuremath{-}}{(3{d}^{4}4{s}^{2})}^{5}D+h\ensuremath{\nu}\ensuremath{\rightarrow}\mathrm{V}{(3{d}^{3}4{s}^{2})}^{4}F+{e}^{\ensuremath{-}}$, ${\mathrm{V}}^{\ensuremath{-}}{(3{d}^{4}4{s}^{2})}^{5}D+h\ensuremath{\nu}\ensuremath{\rightarrow}\mathrm{V}{(3{d}^{3}4{s}^{2})}^{4}P+{e}^{\ensuremath{-}}$, and at discrete wavelengths in region 457.9--647.1 nm using laser photoelectron spectroscopy...

The correlated process of photodetaching two electrons from the F− ion following absorption a single photon has been investigated over an energy range 20–62 eV. In experiment, beam photons Advanced Light Source was collinearly merged with counter-propagating ions sputter source. F+ produced in interaction region were detected, and normalized signal used to monitor relative cross section for double-detachment reaction. An absolute scale established by measuring spatial overlap beams...

The laboratory energy distribution of H+ from the dissociation H3+ in low-keV H3+-He collisions is measured at a 0\ifmmode^\circ\else\textdegree\fi{} angle. An inelastic loss Q=26\ifmmode\pm\else\textpm\fi{}2 eV has been determined for excited states that produce low-energy protons upon dissociation. approximate projectile-frame also presented. Our results suggest near-zero are produced by either an electronic singlet excitation ground state to 2 E1\ensuremath{'}, 1 E1\ensuremath{''}, and...

The laboratory energy distribution of protons in coincidence with an ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ ion, resulting from the dissociation excited ${\mathrm{H}}_{3}^{+}$, has been measured for ${\mathrm{H}}^{+}$-${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ pairs emitted along beam 4.0-keV ${\mathrm{H}}_{3}^{+}$-He collisions. An approximate collinear configuration products is obtained by transforming spectrum to ${\mathrm{H}}_{3}^{+}$ center-of-mass (c.m.) frame. Coincidence data suggest...

We have measured the cross section for detachment of three electrons from ${\mathrm{Cl}}^{\ensuremath{-}}$ ion following absorption a single photon. The triple-photodetachment is compared to our earlier measurement double photodetachment same ion. Possible direct and indirect mechanisms responsible multiple-electron are discussed. process ejection valence seems be most likely process. This conjecture needs theoretical verification.

We have measured the relative cross section for photodetachment from K− ion process + hν→ K+ 2e− over photon energy range 21– 24.5 eV. The structures in are associated with correlated processes involving detachment or excitation of a 3p core electron, which often accompanied by one more valence electrons. most prominent feature is strong resonance arising electron and 4s electron. As previous experiments on double electrons, correlation seen to play an important role dynamics negative ions.

The dominant processes for producing near-zero-energy projectile-frame protons in ${\mathrm{H}}_{2}^{+}$-He collisions at 4-keV ion energy have been experimentally identified. 1s${\mathrm{\ensuremath{\sigma}}}_{\mathit{u}}$ to 2p${\mathrm{\ensuremath{\pi}}}_{\mathit{u}}$ and 3d${\mathrm{\ensuremath{\sigma}}}_{\mathit{g}}$ transitions that produce these occur internuclear separations of the ${\mathrm{H}}_{2}^{+}$ are 2.5--3 times equilibrium separation.

The laboratory energy distribution of protons in coincidence with ${\mathrm{L}}_{\mathrm{\ensuremath{\alpha}}}$ photons produced collision-induced dissociation 4.0-keV ${\mathrm{H}}_{2}^{+}$ on He targets has been measured for that are collected along the incident-beam direction. An approximate proton--${\mathrm{L}}_{\mathrm{\ensuremath{\alpha}}}$-photon pairs projectile frame is obtained by transforming distribution. transformed results reveal dominant processes production near-zero...

We describe a unique apparatus that simultaneously measures the laboratory energy and angles of several charged particles formed in single beam. The ability to separate detect opposite polarity allows one measure them coincidence. Equations for trajectories are derived discussed detail. expressions corresponding resolution detected also presented. Data produced recent experiments illustrate some analyzer’s more important features.

For many years, Atwood’s machine has been used to demonstrate, illustrate, or verify Newton’s laws in introductory physics courses. It consists of two objects different mass that are fastened the ends a string hangs over pulley. In an idealized situation, one assumes pulley friction, string’s mass, and changes length negligible. Cases which pulley’s is non-negligible may be considered. Advanced students can investigate non-ideal cases friction not negligible masses swing. Computer-based data...