In the helical-axis heliotron configuration, bumpiness of the confinement field epsilon(b) is introduced to control the plasma transport. The plasma performance were experimentally investigated in Heliotron J for three configurations with epsilon(b)=0.01, 0.06 and 0.15 at p = 2/3. The obtained volume-averaged stored energy depends on the configuration. To understand the observed difference in global energy confinement, the epsilon(b)-control effects on the edge plasma is discussed. For epsilon(b) = 0.01, the plasma density and temperature in the peripheral region is low compared to other cases. This poor plasma edge relates to the observed low stored energy or poor energy confinement for epsilon(b) = 0.01. (c) 2007 Elsevier B.V. All rights reserved.