Copying lens for microfilm photography.
A new lens design for precise copying exemplifies the success of the rms error function as a suitable criterion for the design of high resolution lenses. The design, a 145-mm f/4.0, gives 400-line/mm, high contrast,white-light visual resolution throughout a 30-mm flat image when used at 20:1 conjugates. On high resolution plates, a resolution of 320 lines/mm is obtained. The five-glass design has no vignetting of the marginal beams, presents no manufacturing problems, and gave full resolution when first assembled. The prescriptionwas found by the LASL 1972 Lens Design Program.
Lens Design That Simultaneously Optimizes Image Spots, Optical Path Difference (OPD), Diffraction Modulation Transfer Function (DMTF), And Seidel Aberrations
The Los Alamos Scientific Laboratory lens design program, in which a lens moves steadily toward diffraction-limited performance, samples lens performance with bundles of precisely traced skew rays, analyzes performance by calculating the image-spot sizes and positions, and optimizes performance in a least squares system that drives the lateral ray deviations toward zero. Minimizing the rms image-spot size minimizes the rms optical path difference (OPD). Minimizing the rms OPD also optimizes the diffraction modulation transfer function (DMTF). Minimizing the image-spot size and position errors minimizes and balances all seven Seidel aberrations because all seven cause lateral deviations of the rays from their ideal image points.
Reduction of Surface Flashover of the Beam Screen of the LHC Injection Kickers
The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wake fields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. Operation with increasingly higher bunch intensity, and narrow bunches, now requires improved ferrite screening. This will be implemented by additional conductors; however the good high-voltage behaviour of the kicker magnets must not be compromised by the supplementary screening. Extensive studies and optimisations have been carried out, to better satisfy the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time, high vacuum and good high voltage behaviour. A new configuration is proposed which reduces significantly the electric field associated with the screen conductors and the secondary electron yield of the surface of the ceramic tube. Results of high voltage test results are also presented.