The effect of operating conditions on margin decay for half disk bubble propagation elements

Bubble device margin and margin decay have been measured for continuous and stop-start propagation at 330 kHz as a function of the magnitude and direction of the holding field on storage loops in a device using half-disc elements. It's found that the performance limit is determined by propagation on the pick-axe turn element and that the margin decay parameter
\varepsilon \sim0.2
Oe/decade with a rotating field of 35 Oe and a holding field of 3.5 Oe. The data was found to be extremely pattern sensitive consistent with an effective interaction field between consecutive bubbles of ∼3 Oe. No difference in performance was found between storage loops with and without conductors under the turn element except at low rotating fields.