Experimental and theoretical charge state distributions of Xe at the photon energy of 5 keV for the full XFEL pulse energy (a) and 27% of the full pulse energy (b)

<p><strong>Figure 6.</strong> Experimental and theoretical charge state distributions of Xe at the photon energy of 5 keV for the full XFEL pulse energy (a) and 27% of the full pulse energy (b).</p> <p><strong>Abstract</strong></p> <p>We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential <em>L</em>-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.</p

XFEL fluence dependence of the ion yields for Xe^{<em>n</em> +} (<em>n</em> = 8, 12, 14, 16, 18 and 20)

<p><strong>Figure 7.</strong> XFEL fluence dependence of the ion yields for Xe^{<em>n</em> +} (<em>n</em> = 8, 12, 14, 16, 18 and 20). Closed circles with the error bars depict the experimental results and solid lines depict the theoretical results. Lines with slope <em>p</em> = 1, 2, 3, 4 and 5 are also shown as broken lines to guide the eye.</p> <p><strong>Abstract</strong></p> <p>We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential <em>L</em>-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.</p

Experimental and theoretical charge state distributions of Ar at the photon energy of 5 keV

<p><strong>Figure 4.</strong> Experimental and theoretical charge state distributions of Ar at the photon energy of 5 keV.</p> <p><strong>Abstract</strong></p> <p>We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential <em>L</em>-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.</p

Plots of ion TOF versus arrival <em>X</em> position on the detector before (a) and after (b) compensation of the TOF for seven isotopes of Xe^{9 +}

<p><strong>Figure 2.</strong> Plots of ion TOF versus arrival <em>X</em> position on the detector before (a) and after (b) compensation of the TOF for seven isotopes of Xe^{9 +}. (c) and (d) show the projections of (a) and (b), respectively. The numbers in (d) indicate the mass of the Xe isotopes in atomic mass units.</p> <p><strong>Abstract</strong></p> <p>We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential <em>L</em>-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.</p

XFEL fluence dependence of the ion yields for Ar^{<em>n</em> +} (<em>n</em> = 3, 4, 8 and 9)

<p><strong>Figure 5.</strong> XFEL fluence dependence of the ion yields for Ar^{<em>n</em> +} (<em>n</em> = 3, 4, 8 and 9). Closed circles with error bars depict the experimental results and solid lines depict the theoretical results. Lines with slope <em>p</em> = 1 and 2 are also shown as broken lines to guide the eye.</p> <p><strong>Abstract</strong></p> <p>We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential <em>L</em>-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.</p

(a) Experimental configuration

<p><strong>Figure 1.</strong> (a) Experimental configuration. (b) Cross section of the ion spectrometer.</p> <p><strong>Abstract</strong></p> <p>We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential <em>L</em>-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.</p

SCOPE: SCUBA-2 Continuum Observations of Pre-protostellar Evolution - survey description and compact source catalogue

We present the first release of the data and compact-source catalogue for the JCMT Large Program SCUBA-2 Continuum Observations of Pre-protostellar Evolution (SCOPE). SCOPE consists of 850 μm continuum observations of 1235 Planck Galactic Cold Clumps (PGCCs) made with the Submillimetre Common-User Bolometer Array 2 on the James Clerk Maxwell Telescope. These data are at an angular resolution of 14.4 arcsec, significantly improving upon the 353 GHz resolution of Planck at 5 arcmin, and allowing for a catalogue of 3528 compact sources in 558 PGCCs. We find that the detected PGCCs have significant sub-structure, with 61 per cent of detected PGCCs having three or more compact sources, with filamentary structure also prevalent within the sample. A detection rate of 45 per cent is found across the survey, which is 95 per cent complete to Planck column densities of N(H2) > 5 × 10^21 cm^−2. By positionally associating the SCOPE compact sources with young stellar objects, the star formation efficiency, as measured by the ratio of luminosity to mass, in nearby clouds is found to be similar to that in the more distant Galactic Plane, with the column density distributions also indistinguishable from each other