Disalignment of excited neon atoms due to helium atom collisions in low temperature T.Shimamura, T.Hanaoka, M.Hasuo and T.Fujimoto Department of Engineering Physics and Mechanics, Kyoto University Disalignment rate coefficient of excited neon atoms in the 2p^{5}3p configuration level due to helium atom collisions has been measured in low temperature range of 15-77K.It is found that the rate coefficient of 2p_{2} and 2p_{7} (Pachen notation) states show more rapid decrease than the theoretical predictions with adecrease in temperature below 40K.