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Title: Operation of a free electron laser in the wavelength range from the extreme ultraviolet to the water window

Abstract

We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 J for individual pulses, and the average energy per pulse reached 70 J. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20 mW. The output beam also contained a significant contribution from odd harmonics of approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.

Authors:
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Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
964432
Report Number(s):
FERMILAB-PUB-07-779-AD
Journal ID: ISSN 1749-4885; TRN: US0903485
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature Photon. 1:336-342,2007; Journal Volume: 1; Journal Issue: 6
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; FREE ELECTRON LASERS; HARMONICS; PEAK LOAD; PERFORMANCE; RADIATION SOURCES; RADIATIONS; SATURATION; WATER; WAVELENGTHS; WINDOWS; Accelerators

Citation Formats

Ackermann, W., /Darmstadt, Tech. Hochsch., Asova, G., /DESY, Ayvazyan, V., /DESY, Azima, A., /DESY, Baboi, N., /DESY, Bahr, J., /DESY, Balandin, V., /DESY, Beutner, B., /Hamburg U., Brandt, A., /DESY, Bolzmann, A., /Wurzburg U., Brinkmann, R., and /DESY /Dubna, JINR. Operation of a free electron laser in the wavelength range from the extreme ultraviolet to the water window. United States: N. p., 2007. Web. doi:10.1038/nphoton.2007.76.
Ackermann, W., /Darmstadt, Tech. Hochsch., Asova, G., /DESY, Ayvazyan, V., /DESY, Azima, A., /DESY, Baboi, N., /DESY, Bahr, J., /DESY, Balandin, V., /DESY, Beutner, B., /Hamburg U., Brandt, A., /DESY, Bolzmann, A., /Wurzburg U., Brinkmann, R., & /DESY /Dubna, JINR. Operation of a free electron laser in the wavelength range from the extreme ultraviolet to the water window. United States. doi:10.1038/nphoton.2007.76.
Ackermann, W., /Darmstadt, Tech. Hochsch., Asova, G., /DESY, Ayvazyan, V., /DESY, Azima, A., /DESY, Baboi, N., /DESY, Bahr, J., /DESY, Balandin, V., /DESY, Beutner, B., /Hamburg U., Brandt, A., /DESY, Bolzmann, A., /Wurzburg U., Brinkmann, R., and /DESY /Dubna, JINR. Mon . "Operation of a free electron laser in the wavelength range from the extreme ultraviolet to the water window". United States. doi:10.1038/nphoton.2007.76. https://www.osti.gov/servlets/purl/964432.
@article{osti_964432,
title = {Operation of a free electron laser in the wavelength range from the extreme ultraviolet to the water window},
author = {Ackermann, W. and /Darmstadt, Tech. Hochsch. and Asova, G. and /DESY and Ayvazyan, V. and /DESY and Azima, A. and /DESY and Baboi, N. and /DESY and Bahr, J. and /DESY and Balandin, V. and /DESY and Beutner, B. and /Hamburg U. and Brandt, A. and /DESY and Bolzmann, A. and /Wurzburg U. and Brinkmann, R. and /DESY /Dubna, JINR},
abstractNote = {We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 J for individual pulses, and the average energy per pulse reached 70 J. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20 mW. The output beam also contained a significant contribution from odd harmonics of approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.},
doi = {10.1038/nphoton.2007.76},
journal = {Nature Photon. 1:336-342,2007},
number = 6,
volume = 1,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 {micro}J for individual pulses, and the average energy per pulse reached 70 {micro}J. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20mW. The output beam also contained a significant contribution from odd harmonics ofmore » approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.« less
  • A flat-field space-resolved extreme ultraviolet (EUV) spectrometer system working in wavelength range of 10–130 Å has been constructed in the Large Helical Device (LHD) for profile measurements of bremsstrahlung continuum and line emissions of heavy impurities in the central column of plasmas, which are aimed at studies on Z{sub eff} and impurity transport, respectively. Until now, a large amount of spike noise caused by neutral particles with high energies (≤180 keV) originating in neutral beam injection has been observed in EUV spectroscopy on LHD. The new system has been developed with an aim to delete such a spike noise frommore » the signal by installing a thin filter which can block the high-energy neutral particles entering the EUV spectrometer. Three filters of 11 μm thick beryllium (Be), 3.3 μm thick polypropylene (PP), and 0.5 μm thick polyethylene terephthalate (PET: polyester) have been examined to eliminate the spike noise. Although the 11 μm Be and 3.3 μm PP filters can fully delete the spike noise in wavelength range of λ ≤ 20 Å, the signal intensity is also reduced. The 0.5 μm PET filter, on the other hand, can maintain sufficient signal intensity for the measurement and the spike noise remained in the signal is acceptable. As a result, the bremsstrahlung profile is successfully measured without noise at 20 Å even in low-density discharges, e.g., 2.9 × 10{sup 13} cm{sup −3}, when the 0.5 μm PET filter is used. The iron n = 3–2 Lα transition array consisting of FeXVII to FeXXIV is also excellently observed with their radial profiles in wavelength range of 10–18 Å. Each transition in the Lα array can be accurately identified with its radial profile. As a typical example of the method a spectral line at 17.62 Å is identified as FeXVIII transition. Results on absolute intensity calibration of the spectrometer system, pulse height and noise count analyses of the spike noise between holographic and ruled gratings and wavelength response of the used filters are also presented with performance of the present spectrometer system.« less
  • We have applied a new, more efficient diagnostic technique for studies of extreme ultraviolet (EUV) radiation from multicharged ions interacting with He gas. Following single and double electron capture and one electron capture plus target-ion excitation in He{sup 2+}+He and Ar{sup 8+}+He collisions, the subsequent emitted EUV photons are analyzed with a high-resolution 2.2 m grazing incidence monochromator in conjunction with a new type of glass capillary converter (GCC) specifically designed for the EUV wavelength region. This new optical device images a horizontal cylindrical ion beam segment onto the vertical entrance slit of the monochromator. With this new imaging techniquemore » a spectral intensity enhancement of about 10 has been achieved over a distance of about 60 cm. By further optimizing this method an enhancement of the flux density of EUV radiation of about 20{endash}30 is expected. As prototype examples, new advanced EUV spectra arising from He{sup 2+}+He and Ar{sup 8+}+He collisions are presented and discussed. {copyright} {ital 1997 American Institute of Physics.}« less
  • Maximum extreme ultraviolet (EUV) conversion efficiencies (CEs) of 2.3% and 1.8% were achieved in planar Li targets by using pulsed 2{omega} and 1{omega} Nd:YAG laser irradiation, respectively. In a forced recombination scheme, the total CE can be expected to be about 4%. The maximum kinetic energy of the lithium ion debris was found to be less than 1 keV, indicating that mirror damage caused by lithium ion debris is more easily mitigated by using a magnetic field than for tin ions. These results suggest that a Li target is a reasonable candidate for an EUV lithography source.
  • The final alignment and characterization of an extreme ultraviolet (EUV) lithographic projection optics system must be performed at the operating wavelength in order to account for errors associated with the combined effect of multilayer coating and substrate fabrication error. Two complementary metrology techniques have been developed which can operate on a compact laser plasma source: EUV lateral shear interferometry (LSI) and aerial image monitoring (AIM). LSI quantifies residual low spatial frequency wave front errors associated with the {open_quotes}figure{close_quotes} of each optical element. To characterize the effect of mid-spatial frequency errors that lead to scatter in the image plane, an EUVmore » aerial image monitor was employed. EUV interferometry was compared to visible light interferometry measurements of the optical system and was found to be in reasonable agreement for low spatial frequency errors. The contrast as measured by AIM and photoresist exposures indicates an additional reduction of contrast associated with scatter due to large mid-spatial frequency errors. {copyright} {ital 1997 American Vacuum Society.}« less