NSLS-II Seminar

The goal is to demonstrate that shape modification can be successfully applied to thin walled (~100-400 micron thickness) replicated optics or slumped glass optics to improve the near net shape of the mirror as well as the mid-frequency ripple. The proposed process involves sputter deposition of a magnetic smart material (MSM) film onto permanent magnetic material. The permanent magnetic material would be the mirror substrate in the case of electroformed optics and would be plated onto the back of glass optics. The MSM material exhibits strains about 400 times stronger than ordinary ferromagnetic materials. The deformation process involves a magnetic write head which traverses the surface, and under the guidance of active metrology feedback,locally magnetizes the surface to impart strain where needed. Because of the hard magnetic material, the localized shape change remains until actively demagnetized. The following tasks will be performed. Upgrade of a sputtering chamber to enable coating 10 cm and larger diameter pieces. Make sputtering targets of our baseline MSM called KelvinAll(TM). Make substrates onto which to sputter the MSM. Sputter onto both electroformed and and plated glass substrates. Model the magnetostrictive response for various substrate and MSM thickness combinations. Finite element modeling of the mirror based on all materials, thicknesses, boundary conditions, and magnetic field magnitude and location. The final step in year 3 will be to show that both free standing cylinders of revolution, mounted glass, and mounted cylinders can be shaped with a goal of 1" half-power diameter encircled energy as demonstrated primarily by ray tracing. The Argonne Advanced Photon Light Source will be used as well. In addition to changes in the macro figure, determine what is the smallest length (goal 100 microns) scale over which the substrates, particularly glass can be smoothed.