The AVF cyclotrons

Having recently completed an eight‐week trip to AVF (Azimuthally Varying Field) cyclotrons, I have found that many people are greatly interested in this field. Many laboratories are either discussing the attractiveness of medium‐energy accelerators or are already debating what kind to get and how to go about it. Unfortunately, there is insufficient direct cooperation among the various laboratories, and up‐to‐date information on accelerator subjects is rarely found even in print. I hope therefore that the present report on my trip may serve as a guide to cyclotron physicists, and bring the subject to the attention of physicists generally, some of whom may, sooner or later, be faced with the issue of obtaining AVF cyclotrons for their laboratories.