Development of a Pixel Detector for Ultra-Cold Neutrons $^{a}$Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan $^{b}$International Center for Elementary Particle Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan $^{c}$Graduate School of Science, Tohoku University, Sendai-shi, Miyagi 980-8578, Japan $^{d}$Research Reactor Institute, Kyoto University, Sennan-gun, Osaka 590-0494, Japan S. Kawasaki $^{$_{∗}$,a}$, G. Ichikawa $^{a}$, M. Hino$^{d}$, Y. Kamiya$^{b}$, M. Kitaguchi$^{d}$, S. Komamiya $^{a,b}$, T. Sanuki$^{c}$, S. Sonodaa A pixel detector with high spatial resolution and temporal information for ultra-cold neutrons is developed based on a commercial CCD on which a neutron converter is attached. $^{10}$B and $^{6}$Li are tested for the neutron con- verter and $^{10}$B is found to be more suitable based on efficiency and spatial $^{resolution. The pixel detector has an efficiency of 44.1}$±1.1% and a spatial $^{resolution of 2.9}$±0.1 µ m (1 sigma). Key words: UCN, pixel detector When ultra-cold neutrons (UCNs) are trapped in the earth’s gravitational field, their energy is quantized. In consequence, their probability density distribution exhibits their vertical modulation. The scale of this density modulation is calculated to be ( ℏ $^{2}$/ 2 m 2 $_{n}$g ) 1 / 3 ∼ 6 µ m. Observations of such ∗ Corresponding author: Tel: +81-3-5841-4201; Fax: +81-3-5841-4158 Email address: kawasaki@icepp.e.u-tokyo.ac.jp (S. Kawasaki) 1. Introduction Abstract arXiv:1002.0398v1 [physics.ins-det] 2 Feb 2010 Preprint submitted to Nuclear Instruments and Methods in Physics Research ANovember 21, 2018