Experimental comparison of performances of ultracold neutron gravity spectrometers

我们所研制的超冷中子秋季聚焦重力谱仪的特性是能量传递和动量传递的高分辨率，分别约为10^&lt；-8 eV和约10^&lt；-3&gt；这些非常高的分辨率是其他任何一台中子谱仪所不能达到的，但最近将开发一种新型的自旋回波谱仪，采用小角排列的方法，它的性能也应该与目前的装置相似。我们的秋季聚焦谱仪提供了同时测量各种散射角的可能性，这是传统的REACH聚焦重力谱仪所不能做到的。散射角分析的这种性质对于研究扩散样品的动力学是非常有用的。其次，研究了我们的光谱仪与新型小角自旋回波谱仪的特性，结果表明，由于超冷中子在样品散射过程中的中子光学过程，我们的超冷中子重力谱仪应该给出许多不同的散射样品的动力学信息，这些研究结果将有效地应用于未来几个正在制备的实际散射样品的应用实验中。

The characteristic performances of the fall focusing gravity spectrometer with ultracold neutrons developed in our Institute were investigated to be the high resolutions for both of the energy transfer and of the momentum transfer, about 10^<-8> eV and about 10^<-3> A^<o-1>, respectively. These very high resolutions are not attained with any other single machine of neutron spectrometers, but recently a new type of spin echo spectrometer is going to be developed applied with the method of small angle arrangements which should also show similar performances with the present device.Our fall focusing spectrometer gives the possibility of measurements of various scattering angles simultaneously, which was not possible with the conventional reach focusing gravity spectrometer. This property of scattering angle analyses is very much useful for studying, for example, dynamics of diffusing samples. In the next place, the Characteristic performances of our spectrometer compared to the new type of the small angle spin echo spectrometer were studied in the present investigation and the result was indicated that the gravity spectrometer with ultracold neutrons should give much different dynamical information on the scattering sample due to the neutron optical processes of ultracold neutrons in the scattering processes in the sample.These much instructive indications derived as the results of the present studies would be effectively applied in the coming applied experiments for several actual scattering samples now under preparation.