Multi-Color Coronagraph Experiment in a Vacuum Testbed with a Binary Shaped Pupil Mask

We conducted a number of multi-band coronagraph experiments using a vacuum chamber and a binary-shaped pupil mask which in principle should work at all wavelengths, in the context of the research and development on a coronagraph to observe extra-solar planets (exoplanets) directly. The aim of this work is to demonstrate that subtraction of Point Spread Function (PSF) and multi-band experiments using a binary-shaped pupil mask coronagraph would help improve the contrast in the observation of exoplanets. A checkerboard mask, a kind of binary-shaped pupil mask, was used. We improved the temperature stability by installing the coronagraph optics in a vacuum chamber, controlling the temperature of the optical bench, and covering the vacuum chamber with thermal insulation layers. We evaluated how much the PSF subtraction contributes to the high contrast observation by subtracting the images obtained through the coronagraph. We also carried out multi- band experiments in order to demonstrate a more realistic observation using Super luminescent Light Emitting Diodes (SLEDs) with center wavelengths of 650nm, 750nm, 800nm and 850nm. A contrast of 2.3x10-7 was obtained for the raw coronagraphic image and a contrast of 1.3x10-9 was achieved after PSF subtraction with a He-Ne laser at 632.8nm wavelength. Thus, the contrast was improved by around two orders of magnitude from the raw contrast by subtracting the PSF. We achieved contrasts of 3.1x10-7, 1.1x10-6, 1.6x10-6 and 2.5x10-6 at the bands of 650nm, 750nm, 800nm and 850nm, respectively, in the multi-band experiments. The results show that contrast within each of the wavelength bands was significantly improved compared with non-coronagraphic optics. We demonstrated PSF subtraction is potentially beneficial for improving contrast of the coronagraph, and this coronagraph produces a significant improvement in contrast with multi-band light sources.Comment: 14 pages, 7 figures, accepted for publication in PAS

EFFICACY OF HOMOGENOUS BONE GRAFTING IN MCCUNE-ALBRIGHT SYNDROME

A case of McCune-Albright syndrome is reported. The patient was a girl aged 8 years. The chief complaints were gait disturbance and a limp. Roentgenograms showed collapse and severe varus deformity of the femoral neck on the right side with 64° of neck-shaft angle. She had an episode of vaginal bleeding at the age 7 years. Valgus osteotomy of the right proximal femur for the correction of coxa vara and a bone transplantation of an allograft from her mother were performed. Seventy degrees of correction were obtained and the discrepancy of limb length was 1cm after the operation. Roentgenograms showed sufficient callus and solid union between the fragments and the grafted bone 1 year after the operation. Frozen allograft bone was very effective in stimulating bone induction even in fibrous lesions of a patient with McCune-Albright syndrome. Immunology of bone grafts, HLA antigens, osteogenesis in grafts, and the etiology of McCune-Albright syndrome were discused