Planche, T. Baartman, R.A. Bylinskii, I.V. Rao, Y.-N. JACoW Geneva, Switzerland 978-3-95450-167-0 10.18429/JACoW-Cyclotrons2016-WEA03 English 254-257 WEA03 space-charge cyclotron TRIUMF simulation focusing Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-Cyclotrons2016-WEA03 http://jacow.org/cyclotrons2016/papers/wea03.pdf We present a method to improve computation efficiency of space charge simulations in cyclotrons. This method is particularly efficient for simulating long bunches where length is large compared to both transverse size and turn separation. We show results of application to space charge effects in the TRIUMF 500 MeV cyclotron.