Abstract
Although the creation of neutrons with accelerator sources goes back to at least Lawrence at Berkeley in the 1930s, the modem concept of using a proton accelerator and a heavy metal target can be traced back to Jack Carpenter, then at the University of Michigan, in the early 1970s. Encouraged by David Price, Jack first came to PUVL as a summer visitor, and then as a regular staff member, to develop a series of prototypes: ZING, ZING-P, and ZING-P', based on the AGS proton accelerator at Argonne. These finally led (at Argonne) to PNS, which opened for business in 1981, and has been running successfully ever since, now 20 years on.