ABSTRACT
The success of an operation does not only depend on a perfect surgical technique, an appropriate anesthesia, convenient surgical instruments and functional technical equipment, but also on a proper operative positioning. Meeting the requirements of the surgeon, the positioning has also to be in accordance with the patient's individual needs. Seemingly trivial in "simple" positions, there must be paid attention to details, as they can have serious harm to the patient if done incorrectly. The surgeon is in charge for the positioning, but the performance is done in a horizontal division of work between surgeon and anesthesiologist. This article describes standard positions, demonstrates their realization and special damages, and points out juristic aspects as well as technical items like operating table and positioning facilities.
Subject(s)
Postoperative Complications/prevention & control , Posture/physiology , Surgical Procedures, Operative/methods , Anesthesia , Brachial Plexus/injuries , Documentation , Eye Injuries/prevention & control , Humans , Monitoring, Intraoperative , Operating Rooms , Peripheral Nerve Injuries , Physicians , Radial Neuropathy/etiology , Radial Neuropathy/prevention & control , Surgical Procedures, Operative/legislation & jurisprudence , Ulnar Neuropathies/etiology , Ulnar Neuropathies/prevention & control , WorkforceABSTRACT
Gallium selenide has been used as a frequency doubler for the output of a high-power, short-pulse, mid-infrared free-electron laser. Internal conversion efficiencies up to 36% have been achieved in the wavelength range from 6.3 to 12 microm. The second-harmonic output was stable over many hours at peak power levels of 1-2 MW.
ABSTRACT
Through the use of the Fox-Li method with the quasi-fast Hankel transform, vignetting effects of wiggler bores on empty modes in free-electron laser resonators are numerically investigated. Two typical symmetric optical cavity configurations are considered, one being near confocal (g = -0.2) and the other being near concentric (g = -0.94). Different wiggler-bore dimensions and different optical wavelengths for which vignetting is important are investigated. The vignetted field patterns, power losses, and phase shifts are computed for the two lowest-order empty modes (TEM(00) and TEM(01)). Near-field patterns in the near-confocal case are illustrated. It is found that the mode field distributions are strongly modulated at the mirror apertures in the Fresnel diffraction regime but are not modulated at the wigglerbore ends. It is shown that vignetting with an appropriate amount of misalignment is even good for improving the mode control. Finally, the calculations are applied to the Darmstadt free-electron laser.
