Performance of the high-resolution SX700/II monochromator

Abstract

This article reports on the high-resolution performance of the grazing-incidence plane grating monochromator SX700/II, installed at BESSY by the Freie Universität Berlin, in the photon energy range from about 40 to 900 eV. The high resolving power up to 10 000 achieved with this monochromator is based on improving the figure error of the ellipsoidal focusing mirror, on reducing the vertical dimension of the beam source, and on employing a 5-μm exit slit. We report on high-resolution gas-phase studies in the double-excitation region of He, as well as at core-excitation thresholds of Ne, Ar, Kr, and Xe in the photon-energy range from ≂45 eV to ≂900 eV. In addition, high-resolution core-excitation spectra at the K thresholds of C, N, and O are presented for gas-phase CO, N2, and O2. In all cases, high-n Rydberg states and/or vibrational sidebands of the electronic excitations were resolved. The various contributions to the present instrumental linewidths are discussed as well as the prospects for further improvements in resolution with this monochromator.

A quantitative analysis of the N 1s→π* photoabsorption profile in N2: new spectroscopical constants for the core-excited state

“…At beamline I 411 an elliptically-shaped mirror is used, whereas at beamline I 311 a spherically-shaped mirror is installed. Moreover, the so-called fixed-focus constant c ff for this monochromator type (see [13] and references therein) can be varied more easily at beamline I 311 than at beamline I 411, giving a handy possibility to vary the resolving power of the monochromator at beamline I 311. Capacitor-based absorption chambers similar to the one shown in the work of Domke et al [13] were used for the absorption measurements.…”

“…The resolving power of soft X-ray instruments is usually lower compared to instrumentation used in the optical region and, on top of that, core-excited states are often inherently broadened due to their short natural lifetime which is typically on the femtosecond time-scale. In addition, if the vibrational spacing of a core-excited state is smaller than the natural lifetime width, vibrational resolution is intrinsically limited (see [13,14]). For these reasons, it is difficult to extract accurate spectroscopical constants for neutral core-excited states.…”

“…This vibrational fine structure is commonly used as a benchmark to demonstrate the resolving power of soft X-ray monochromators in the 400 eV photon energy region (see, e.g. [13]), and indeed, a resolving power in the order of 10 000 is achievable nowadays (see, e.g. [14]).…”

Joys and Pitfalls of Fermi Surface Mapping inBi2Sr2CaCu2Борисенко1, Golden2, Legner3 et al. 2000Phys. Rev. Lett.927460View full textAdd to dashboardCite

“…The XAS experiments were carried out using the SX700/II beam line 25 operated by the Freie Universität Berlin at the BESSY synchrotron radiation source ͑Berlin͒ using linearly polarized light. The energy resolution of the monochromator was set to be 280 and 660 meV at the O 1s and Cu 2 p absorption thresholds, respectively.…”

A unique high-performance wide-range (10–1500 eV) spherical grating monochromator beamline

“…The newly developed beamlines have achieved their design goals of high resolution and high¯ux. Among various designs, SX-700 (Petersen, 1982;Jark, 1992;Domke et al, 1992;Kanindl et al, 1992) and Dragon (Chen, 1987;Chen & Sette, 1989;Warwick et al, 1995;Schulz et al, 1996) are the most commonly used. In addition to high resolution, SX-700 and other PGM-type designs have the advantage of covering a wide spectral range per grating.…”