New lamps for old: Synchrotron radiation and free-electron laser x-ray sources

Author(s):  
R. P. Walker
1995 ◽  
Vol 02 (04) ◽  
pp. 501-512 ◽  
Author(s):  
N.H. TOLK ◽  
J.T. MCKINLEY ◽  
G. MARGARITONDO

Synchrotron-radiation sources have become, since the late 1960’s, one of the fundamental experimental tools for surface and interface research. Only recently, however, a related type of photon sources - the free-electron lasers (FELs) — has begun to make important contributions to this field. For example, FELs have been used to reach unprecedented levels of accuracy and reliability in measuring semiconductor interface energy barriers. We review some of the present and proposed experiments that are made possible by the unmatched brightness and broad tunability of infrared FELs. Practical examples discussed in the review are supplied by our own programs at the Vanderbilt Free-Electron Laser. We also briefly analyze the possible future development of FELs and of their applications to surface and interface research, in particular, the possibility of x-ray FELs.


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1490
Author(s):  
Yuji Sano ◽  
Kiyotaka Masaki ◽  
Koichi Akita ◽  
Kentaro Kajiwara ◽  
Tomokazu Sano

Synchrotron radiation (SR) and X-ray free electron laser (XFEL) are indispensable tools not only for the exploration of science but also for the evolution of industry. We used SR and XFEL to elucidate the mechanism and the effects of laser peening without coating (LPwC) which enhances the durability of metallic materials. X-ray diffraction (XRD) employing SR revealed that the residual stress (RS) in the top surface became compressive as the laser pulse irradiation density increased with appropriate overlapping of adjacent laser pulses. SR-based computed tomography (CT) was used to nondestructively reconstruct three-dimensional (3D) images of fatigue cracks in aluminum alloy, revealing that LPwC retarded crack propagation on the surface and inside of the sample. SR-based computed laminography (CL) was applied to friction stir welded (FSWed) aluminum alloy plates to visualize fatigue cracks propagating along the welds. The fatigue crack had complicated shape; however, it became a semi-ellipsoid once projected onto a plane perpendicular to the fatigue loading direction. Ultra-fast XRD using an XFEL was conducted to investigate the dynamic response of aluminum alloy to an impulsive pressure wave simulating the LPwC condition. The diffraction pattern changed from spotty to smooth, implying grain refinement or subgrain formation. Shifts in diffraction angles were also observed, coinciding with the pressure history of laser irradiation. The durations of the dynamic phenomena were less than 1 µs; it may be possible to use high-repetition lasers at frequencies greater than kHz to reduce LPwC processing times.


2011 ◽  
Vol 131 (2) ◽  
pp. 68-71
Author(s):  
Etsuo FUJIWARA ◽  
Eiichi ANAYAMA ◽  
Yuichiro KATSUTA ◽  
Toshiki IZUTANI ◽  
Daichi OKUHARA ◽  
...  

2014 ◽  
Vol 134 (12) ◽  
pp. 836-839
Author(s):  
Junichi INOUE ◽  
Yuji TANAKA ◽  
Yuki MATSUMOTO ◽  
Kensuke KANDA

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