• A. Sessler
  LBNL, Berkeley, California

The impact of the work of Albert Einstein on accelerator physics is described. Because of the limit of time, and also because the audience knows the details, the impact is described in broad strokes. Nevertheless, it is seen how his work has affected many different aspects of accelerator physics. In the second half of the talk, Albert Einstein's impact on the world will be discussed; namely his work on world peace (including his role as a pacifist, in the atomic bomb, and in arms control) and his efforts as a humanitarian (including his efforts on social justice, anti-racism, and civil rights).

• S. Schreiber
  DESY, Hamburg

The VUV-FEL is a free electron laser user facility being commissioned at DESY. It is based on the TTF-FEL, which was in operation until end of 2002 providing a photon beam for two pilot experiments in the wavelength range of 80 to 120 nm. In its final configuration, the new VUV-FEL is designed to produce SASE FEL radiation with a wavelength down to 6 nm with high brilliance. The commissioning started in fall 2004, and in January 2005 succeeded in first lasing in the SASE mode at a wavelength of 32 nm with a radiation power in the saturation range. This is a major milestone of the facility and of SASE FELs in general. This contribution reports on the present the electron linac driving the FEL, on properties of the electron beam and on the characterization of the FEL photon beam.

• H. Yamada
  SLLS, Shiga

Funding: MEXT 21st Century COE

We report the first lasing of the photon storage ring (PhSR) at Ritsumeikan Univ. This novel laser is a kind of FEL but is free from an undulator, and adopting a barrel shaped optical cavity placed inside the vacuum chamber around the 0.156 m radius exact circular electron orbit of synchrotron [1]. In the recent theoretical calculation [2], nearly 100 times larger gain is predicted in comparison with the earlier calculated [3]. We have observed the lasing with th·10²⁰ MeV synchrotron. We have measured the laser wavelength by FTIR with Si bolometer. Characteristic peaks at 30, 100, and 160 mm appear when fine-tuning of the magnetic field of synchrotron is applied. The wavelength shift appears as the time progress after injection due to the shifted electron orbit. The electron orbit radius is determined by the electron energy and the main magnetic field. All peaks grow in proportional to I² as the beam current I increase. The square growth indicates highly coherent nature of PhSR radiation.

[1] H. Yamada, Advances in Colloid and Interface Sci. 71-72 (1997) p. 371 [2] A.I. Kleev and H. Yamada, IEEE Journal of Quantum Electronics 39(6), 2003, p. 1 [3] K. Mima, K. Shimoda, and H. Yamada, IEEE J. Quantum Ele., vol. 27, p. 2572, 1991.

• S.V. Benson, K. Beard, C.P. Behre, G.H. Biallas, J. Boyce, D. Douglas, H.F.D. Dylla, R. Evans, A.G. Grippo, J.G. Gubeli, D. Hardy, C. Hernandez-Garcia, K. Jordan, L. Merminga, G. Neil, J.P. Preble, M.D. Shinn, T. Siggins, R.L. Walker, G.P. Williams, S. Zhang
  Jefferson Lab, Newport News, Virginia
• N. Nishimori
  JAEA/FEL, Ibaraki-ken

Funding: This work supported by the Office of Naval Research, the Joint Technology Office, the Commonwealth of Virginia, the Air Force Research Laboratory, the US Army Night Vision Laboratory, and by DOE Contract DE-AC05-84ER40150.

After demonstrating 10 kW operation with 1 second pulses, the Jefferson Lab program switched to demonstrating high power operation at short wavelengths using a new 8 cm period wiggler and a THz suppression chicane. We report here on the lasing results to date using this new configuration. We have demonstrated a large reduction in THz heating on the mirrors. We have also eliminated heating in the mirror steering assemblies, making operation at high power much more stable. Finally, we have greatly reduced astigmatism in the optical cavity, allowing operation with a very short Rayleigh range. The laser has been tuned from 0.9 to 3.1 microns using the new wiggler. User experiments commenced in April of 2005 with the FEL Upgrade operating over the 1-3 micron range. We are in the process of installing a 5.5 cm permanent magnet wiggler that will give us even larger tuning range and higher power.

Corresponding author: Tel: 1-757-269-5026; fax: 1-757-269-5519; E-mail address: felman@jlab.org

• M. Li, X. Jin, Z. Xu
  CAEP/IAE, Mianyang, Sichuan

First lasing of the CAEP FIR-FEL at center wavelength 115 μm was observed in March 2005. The facility consists of RF-gun, alpha magnet, L-band SW accelerator, beam transport line, wiggler, optical cavity and measurement system. In this paper, the design consideration, the system layout, some experimental results are introduced.