Issued By The Cold Neutron Source System Heat And Cold Neutron Gain

Neutron scattering technology is widely used in many research reactors in the world, whose applications include microstructure analysis, material dynamics, fundamental physics and so on, especially, very popular research of new material and new biological medicine in recent years. Almost each new constructed research reactor had installed CNS with the reason that cold neutron scattering experiment is the outstanding in neutron scattering experiment research. With the development of China's comprehensive economy power and increasing requirements with neutron scattering technology from different scientific area, the high quality of CNS installed on CARR (China Advanced Research Reactor) will be popular for internal and international users, even though the CNS on HWRR is not effectively used due to many reasons.The nuclear heating and gain factor of CNS are the most important parameters. Also, the research of nuclear heating and gain factor is the chief content for every CNS. The total nuclear heating is important elements for CNS design and construction. At the same time, the gain factor is the principle exhibition of its performance, which also affects the design and installation of neutron guide tube and neutron apparatus connecting with it.It was in this paper that the main research contents of nuclear heating and gain factor and its crux technology are affirmed for CARR. Besides, it had been also researched for the method how to calculate the heating and gain factor accurately by using MCNP program. In addition, the result by using this method for NBSR CNS in NIST (National Institute of Standard Technology) is compared with calculating result provided by the expert from NIST. The consistency between our result and expert's argues that our methods are corrected. It is another exemplification that the calculating result by using this method for isotopic target irradiated in reactor is also coincidental to the experimental result (error less then 5%).There are many calculations by using MCNP program and analysis conducted inthis paper. Firstly, the calculation is carried out for those elements that affect heating such as the kind of moderator, moderator cell material and so on. The optimized selection is provided. Secondly, many problems are investigated which include the best thickness of liquid hydrogen, moderator cell material, the ratio of para-hydrogen to ortho-hydrogen and the gain factor. Finally, it was compared and optimized for those basics that influence the heating and gain factor such as the position of CNS vertical channel, the dimension of moderator cell and so on. All in all, this study can provide the calculating method, analyzing method, optimized ways and partial optimization for CARR CNS design and construction.