狭缝法合肥光源高亮度注入器发射度测量系统

Slit-based emittance measurement system for high-brightness injector at Hefei Light Source

为了测量受空间电荷效应支配的发射度,合肥光源高亮度注入器采用了狭缝法进行测量,研究了基于狭缝法发射度测量系统的构成,并以实例比较了单狭缝和多狭缝在发射度测量系统中的应用。两种测量方法的结果表明:单狭缝法测量的结果更接近于模拟计算值,可有效避免子束团之间的重叠,适用范围更广。实验结果表明:在240pC电荷量情况下,合肥光源高亮度注入器仍然具有较小的归一化发射度,为(1.84±0.085)mm.mrad。

In order to measure the beam emittance which is space charge dominated, a slit-based emittance measurement system is applied in Hefei Light Source （HLS）. Two types of slit masks are chosen： multi-slit one and single-slit one. Measurement results show that, single-slit based emittance measurement yields closer results to the simulation value. Moreover, single-slit based emittance measurement can avoid the overlapping between adjacent beamlets, which makes its application range wider than multi-slit technique. The experiment result shows that with the beam charge of 240 pC, normalized emittance of （1.84 ±0. 085） mm ·mrad can be achieved at HLS.