Awida, M.H. Dey, J.E. Khabiboulline, T.N. Lebedev, V.A. Madrak, R.L. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-MOPOB16 English 106-108 MOPOB16 impedance cavity ion dipole HOM Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-MOPOB16 https://jacow.org/napac2016/papers/mopob16.pdf Two recycler cavities are being employed in Fermilab's Recycler Ring for the purpose of slip stacking proton bunches, where 6 batches of 8 GeV protons coming from the Booster are stacked on top of 6 circulating batches. Slip stacking requires two RF cavities operating at 52.809 and 51.545 MHz. In this paper, we report on the analysis of higher order modes in the Recycler cavity, presenting the values for R/Q and shunt impedances. Knowing the frequencies and properties of higher order modes is particularly critical for beam physics and avoidance of beam instabilities.