Spectroscopy in the extreme ultraviolet on an electron beam ion trap

Abstract

Articles you may be interested inExtended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trapa) Rev. Sci. Instrum. 85, 11E422 (2014);Highly charged metal ions produced from volatile organometallic compounds in a room temperature electron beam ion trap Rev.High energy operation of the Tokyo-electron beam ion trap/present status Rev. Sci. Instrum. 71, 687 (2000)A compact grazing-incidence spectrometer was implemented on the Livermore electron beam ion trap facility for spectral measurements in the extreme ultraviolet spectral region. The spectrometer employed a 1200 l /mm grating designed for flat-field focusing and a charge coupled device camera for readout. The instrument was used to measure line emission in the range from 25 to 220 Å with a resolving power as high as 600. The performance and calibration of the instrument is described and spectra from highly charged nitrogen and iron ions are presented. Measurements of the K-shell spectrum of He-like N 5ϩ are presented that confirm earlier wavelength determinations and illustrate the accuracy achievable with the instrument. Our measurement suggests a change in the line identifications of the forbidden He-like N 5ϩ transition 1s2s 3 S 1 →1s 2 1 S 0 and of the Li-like N 4ϩ collisional satellite transition 1s2s2p 2 P 3/2 →1s 2 2s 2 S 1/2 observed on the Alcator C-Mod tokamak.

Low-density laboratory spectra near the He iiλ304 line

“…For the present measurement, we used a medium-resolution flat-field grating spectrograph (FFS; Beiersdorfer et al 1999b). The instrument was equipped with a 1200 /mm R = 5 m grating and operated at an angle of incidence of 87…”

Extreme Ultraviolet Spectra of Few-Times Ionized Tungsten for Divertor Plasma Diagnostics

“…The spectra were studied using a moderate-resolution broad-band grating spectrometer of the same type used for grazing-incidence measurements at the SSPX, NSTX, LTX and Alcator C-Mod magnetic fusion facilities [42][43][44][45][46][47]. The instrument employs a 1200-line/mm flat-field grating with a radius of curvature of 5.6 m. The diffracted rays are focused on a Princeton Instruments back-illuminated CCD camera with a 1024 × 1340 array of pixels, each of a size of 20 µm × 20 µm.…”

Iron emission lines in solar and laboratory plasmas

“…The higher energy is sufficient to produce charge states as high as Fe xvi. The spectra were recorded with the grazing-incidence spectrometer described by Beiersdorfer et al [13], which employs a 1200 line/mm flat-field grating developed by Harada & Kita [14] with a 3 o angle of incidence. Readouts were taken with a back-illuminated, liquid nitrogen-cooled CCD camera with a one inch square array of 1024 × 1024 pixels.…”

“…A foil comprised of a 2000Å thick aluminum layer on top of 1000Å of paralene was placed in front of the grating in order to screen out emission from lines with wavelengths below 170Å. The wavelength scale was established using the well known K-shell emission lines of nitrogen, in particular the N vii Lyman-α line and the N vi resonance line commonly referred to as w, as described by Beiersdorfer et al [13], observed in higher (7th through 10th) orders. The wavelengths of the iron emission lines in this wavelength region are well known, and we have not attempted to improve upon those data.…”