A Superthermal Source at NCState University

我们正在进行一项计划，以建造一个世界一流的，超热超冷中子（UCN）源在低功率，大学为基础的反应堆。 在过去的五年里，美国洛斯阿拉莫斯国家实验室和国家标准与技术研究所的研究小组在超高温UCN源的开发方面取得了长足的进步，令人信服地证明了这些天体的物理特性已经被理解。 利用超热源将现有的UCN密度提高几个数量级可能是可以实现的。 拟议的来源将在强度上与目前在美国和国外计划的基本上所有设施相当，并且比目前正在运行的任何来源都要强大得多。 该委员会包括参与基本对称性研究的核物理学家和专门从事反应堆冷源和慢化剂开发的核工程师。 使用低能中子的研究计划是由UCN在基础核物理测量中的有效性所驱动的，例如限制核子的静电偶极矩和测量核子的荷电弱电流形状因子。 这些测量对当今物理学所面临的一些最深刻和最基本的问题产生了影响。 随着超热源上UCN通量的增加，UCN作为表面氢层和生物大分子的非破坏性探针的新应用也可能得到发展。

We are undertaking a program to construct a world-class, superthermalultracold neutron (UCN) source at a low power, university-basedreactor. In the past five years, research groups at Los Alamos NationalLaboratory and the National Institute of Standards and Technology in theUnited States have made great strides in the development of superthermalUCN sources, demonstrating convincingly that the physics of thesesources is understood. Orders of magnitude improvement in available UCNdensities with superthermal sources may be within reach. The proposedsource will be comparable in strength to essentially all of thefacilities currently being planned in the U.S. and abroad, andconsiderably stronger than any presently operating source. Thecollaboration comprises nuclear physicists involved in fundamentalsymmetries research and nuclear engineers who specialize in reactor coldsource and moderator development. Research programs using low-energyneutrons are driven by the proven usefulness of UCNs for fundamentalnuclear physics measurements, such as placing limits on the staticelectric dipole moments of nucleons and the measurement of the chargedweak current form factors of the nucleon. These measurements haveimpact on some of the deepest and most fundamental questions confrontedby physics today. With the increased UCN flux available at superthermalsources, the development of new applications for UCN as non-destructiveprobes of surface hydrogen layers and large biological molecules mayalso be posssible.