-
[show abstract]
[hide abstract]
ABSTRACT: A currently typical X-ray free electron laser machine consists of a high energy linear accelerator that adopts a photo-cathode electron gun and a long undulator. Possibility of a compact X-ray free electron laser machine working at a low energy is discussed. This paper shows how it is possible by using lower emittance guns that are under development.
IEEE Transactions on Nuclear Science 09/2008; · 1.45 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: X-ray free-electron lasers based on self-amplified spontaneous emission promise users unprecedented X-radiation that is extremely bright, extremely short and transversely coherent. However, hard X-ray free-electron laser facilities under construction are all huge and expensive, consisting of high-energy linear accelerators and long undulators. The benefit of hard X-ray free-electron lasers may be limited to only a few regions in the world, unless it is possible to reduce the size. This paper discusses how small a hard X-ray free-electron laser facility can be. It is shown that a 1.5 A X-ray free-electron laser is achievable using electron energy down to 4.5 GeV or lower if we use the third-harmonic radiation, but at the expense of the transverse coherence.
Journal of Synchrotron Radiation 12/2007; 14(Pt 6):522-6. · 2.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Pohang Light Source (PLS) has been operated since 1994. Last year few improvements have been made to stabilize the reference orbit drifts caused by insertion devices and other sources: The control system has been upgraded to 20 bit capability from 12 bit. The slow global orbit feedback is employed routinely in the user run times. These improvements and the operational status change is presented in this paper.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
-
Tae-Yeon Lee
[show abstract]
[hide abstract]
ABSTRACT: Derived are simple and accurate formulas estimating the Touschek and beam-gas scattering lifetimes. These formulas are practical rather than theoretical. They use only the measured total beam lifetime tau and its time derivative dtau/dt to estimate the two lifetimes. The only condition required is suppression or saturation of the radiative polarization. As a demonstration, the formulas are applied to the Pohang Light Source (PLS) beam lifetime.
Physical Review E 05/2004; 69(4 Pt 2):046501. · 2.26 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Role of gun emittance is discussed to build a compact XFEL machine. It is shown that low gun emittance plays the critical role of reducing the XFEL machine size.
-
[show abstract]
[hide abstract]
ABSTRACT: In order to the PAL-XFEL, the 1 st stage will be to build a test machine, whose design parameters are presented here. It will be a 200 MeV machine that has the target wavelength of visible range. The design details and simulation results are shown in this paper.
