Sajaev, V. Borland, M. Sun, Y.P. Xiao, A. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-WEPOB10 English 907-909 WEPOB10 ion lattice undulator sextupole injection Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-WEPOB10 https://jacow.org/napac2016/papers/wepob10.pdf A helical superconducting undulator is planned for installation at the APS. Such an installation would be first of its kind – helical devices were never installed in synchrotron light sources before. Due to its reduced horizontal aperture, a lattice modification is required to accommodate for large horizontal oscillations during injection. We describe the lattice change details and show the new lattice experimental test results. To understand the effect of the undulator on single-particle dynamics, first, its kick maps were computed using different methods. We have found that often-used Elleaume formula* for kick maps gives wrong results for this undulator. We then used the kick maps obtained by other methods to simulate the effect of the undulator on injection and lifetime.