This paper is an addendum to reference (Brynes etal 2018 New J. Phys. 20 073035), in which we studied the transverse emittance growth due to coherent synchrotron radiation (CSR) in the bunch compressor of a free-electron laser. Analytic results based on the theory of CSR were compared with results from experiment and simulation. Recent results have been published (Stupakov 2019 arXiv:1901.10745) which correct the theoretical emittance growth, predicting a smaller increase than that which was expected based on previous results. When comparing these new calculations with the emittance growth that was measured experimentally, and with 3D simulations, we find an improved agreement when the bunch compression approaches its maximum value.

本文是参考文献（Brynes et al 2018 New J. Phys. 20 073035）的增编，其中我们研究了自由电子激光器束压缩器中相干同步辐射（CSR）引起的横向发射率增长。将基于CSR理论的分析结果与实验和模拟结果进行了比较。最近发表的结果 (Stupakov 2019 arXiv:1901.10745) 修正了理论发射率增长，预测增长幅度小于基于先前结果的预期增长。当将这些新计算与实验测量的发射率增长进行比较时，我们发现当束压缩接近其最大值时，我们发现了更好的一致性。