SYNCHROTRON CRYSTALLOGRAPHY BEAMLINE X9A STRUCTURE FUNCTION STUDIES

NSLS与日本SPring-8合作，设计了， 建造并测试了一个原型 小间隙 波荡器，其紧凑性 允许其驻留在存在于X9和X29处的RF腔之间。 该原型真空波荡器（IVUN），周期为11毫米， 最小有效间隙为3.3 mm（最大为10 mm）和磁场 目前，0.678 T安装在光束线的直线段 X13 这些参数导致测量的基本电压为4.6 keV， 第二谐波在8.7keV，第三谐波在13.9keV。 的 IVUN的亮度与X25相当（略高） 摇摆者 由于它的亮度明显低于 APS设备，必然的结果是光谱宽度更大， 足以围绕选定的吸收进行MAD实验的事实 如果仔细选择峰值能量，则会出现边缘。 X13波荡器 将为设计和建造一个完全 专门用于MAD数据收集的小间隙波荡器站 在国家安全研究所。 这种设施的可用性将大大 增加可供科学研究人员使用的MAD天数 社区，并将作为进一步发展的模式， 实施小间隙波动器作为 结构、分子和细胞生物学。

The NSLS, in collaboration with SPring-8, Japan, has designed, built and tested a prototype small-gap undulator, whose compactness allows it to reside between the rf cavities that exist at X9 and X29. This prototype in-vacuum undulator (IVUN), with a period of 11 mm, a minimum useful gap of 3.3 mm (maximum of 10 mm) and a magnetic field of 0.678 T is currently installed in the straight section for beamline X13. These parameters lead to a measured fundamental at 4.6 keV, second harmonic at 8.7 keV, and a third harmonic at 13.9 keV. The brightness of IVUN is comparable (slightly higher) than the X25 wiggler. Since its brightness is significantly less than that of the APS devices, the corollary is that the spectral width is greater, in fact sufficient to perform a MAD experiment around selected absorption edges if the peak energy is carefully selected. The X13 undulator will provide the basis for the design and construction of a completely dedicated small-gap undulator station for MAD data collection at the Se edge at NSLS. The availability of such a facility will greatly increase the total number of MAD days available to the scientific community and will serve as a model for the further development and implementation of small-gap undulators as major resources in structural, molecular and cellular biology.