Figure correction of a metallic ellipsoidal neutron focusing mirror
- Ultrahigh Precision Optics Technology Team, RIKEN Center for Advanced Photonics (RAP), RIKEN, Wako, Saitama 351-0198 (Japan)
- Neutron Optics Group, Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan)
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-0808 (Japan)
An increasing number of neutron focusing mirrors is being adopted in neutron scattering experiments in order to provide high fluxes at sample positions, reduce measurement time, and/or increase statistical reliability. To realize a small focusing spot and high beam intensity, mirrors with both high form accuracy and low surface roughness are required. To achieve this, we propose a new figure correction technique to fabricate a two-dimensional neutron focusing mirror made with electroless nickel-phosphorus (NiP) by effectively combining ultraprecision shaper cutting and fine polishing. An arc envelope shaper cutting method is introduced to generate high form accuracy, while a fine polishing method, in which the material is removed effectively without losing profile accuracy, is developed to reduce the surface roughness of the mirror. High form accuracy in the minor-axis and the major-axis is obtained through tool profile error compensation and corrective polishing, respectively, and low surface roughness is acquired under a low polishing load. As a result, an ellipsoidal neutron focusing mirror is successfully fabricated with high form accuracy of 0.5 μm peak-to-valley and low surface roughness of 0.2 nm root-mean-square.
- OSTI ID:
- 22483240
- Journal Information:
- Review of Scientific Instruments, Vol. 86, Issue 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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