Design Study and R&D of Tau/Charm Factory

1.北京牛头牌厂的设计进展顺利，设计结果总结为《北京牛头牌厂可行性研究报告》，国际能源署BTCF报告，1996年10月。该项目的首席调查员黑川信一出席了1996年11月在高级别环境研究所举行的生物多样性公约国际审查委员会。委员会对设计工作的结果表示赞赏，并建议尽早动工。在北京正负电子对撞机上对光电子不稳定性(PEI)进行了一系列实验，实验结果如下：(1)在PF观察到的现象是光电子不稳定性(PEI)；(2)阐明了不稳定性与不同加速器参数的关系；(3)阐明了各模的传播和强度随时间的变化。这些实验在国际上受到高度赞赏。在AR上进行的束流测试证明了单室、单模超导腔在TauCharm Factory中的适用性，这种类型的腔可以存储570 mA，与TauCharm Factory的值大致相同。为使BTCF所必需的超导腔和超导末焦四极管的建造，为超导技术的技术转移做好了准备。

1. The design of BTCF, Beijing TauCharm Factory, proceeded smoothly, and the results was summarized as "Feasibility Study Report on Beijing TauCharm Factry", IHEP BTCF ReportO3, October 1996. Head investigator of this project, Shin-ichi Kurokawa, attended the International Review Committee of BTCF held at IHEP in November 1996. The committee appreciated the result of the design work and recommended early start of the construction.2. A series of experiments on photo-electron instability (PEI) was performed at BEPC of IHEP.The results of the experiments are summarized as follows : (1) The phenomena observed at PF was confirmed as PEI ; (2) The dependence of the instability on various accelerator parameters was clarified ; and (3) The spread of modes and variation of strength of each mode with respect to time were clarified. The experiments are highly appreciated internationally.3. The applicability of single-cell, single-mode, superconducting cavity to TauCharm Factory was proved by a beam test done at AR, where this type of cavity could store 570 mA, which was about the same value as that of TauCharm Factory. In order to make the construction of superconducting cavities and superconducting final-focus quads that are must for the BTCF, preparation for technology transfer of superconducting technology was done.