Construction Classics

The University of Washington 60-Inch Cyclotron

A construction record is the scarcest thing this collection holds. Design proposals survive because they were written to persuade, and physics results survive because they were the point; the account of a machine actually being built survives only when somebody was required to file one. This is such a filing: the University of Washington reporting progress on a 60-inch cyclotron intended for a 20 MeV deuteron beam, with the buildings, the magnet, the vacuum system and the gas supply all treated as parts of the same job.

A machine built from someone else's drawings

The most useful thing in it is stated in the opening section and is not a number. The Washington machine follows the Crocker cyclotron at the University of California, and it does so deliberately: the laboratory obtained a complete set of the Berkeley plans, placed at their disposal by E. O. Lawrence, and the report says those drawings were followed closely on the magnet design and were invaluable in the major work.

That is a documented case of the thing an amateur builder actually does — take a machine known to work and copy it, rather than originate a design — done by a university physics department in the late 1940s and written down without embarrassment. It is also the reason the report is worth reading alongside its parent: what a second builder had to decide, adapt or discover for themselves is exactly the information a set of drawings never contains.

The building is part of the machine

The report documents the cyclotron building and its shop alongside the accelerator, and notes that half of the 5,000 square foot concrete building is buried. That is shielding by geometry and mass rather than by specified thickness, and it is the practice the shielding deep dive describes as the cheapest available: earth and depth cost almost nothing at construction time and nothing at all thereafter, whereas lead bought later is expensive forever. Very few accelerator documents include the building at all; treating it as a subsystem is a choice worth copying.

Why this document can be hosted

AECU-1951 is a United States Atomic Energy Commission report in the AECU series, prepared under AEC sponsorship — the same publication basis as the AECD and TID material elsewhere in this collection. All 128 pages were searched for copyright notices, classification markings and distribution restrictions: none appear. Determination made August 2026, by reading the scan.

What it covers

1. General requirements · section 1
   What the machine had to do, and the decision that shaped everything after it — to follow an existing proven design rather than originate one.
2. The buildings · section 2
   The cyclotron building and its associated shop, treated as part of the machine rather than as a site condition. Half of the 5,000 sq ft concrete building is below grade.
3. The magnet — including a model magnet · section 3
   Magnetization, the model magnet and its measurements, then the full-size magnet and its pole surfaces. The model comes before the machine, in the report as in the build.
4. Vacuum: envelope, dees, gaskets, gas supply, protection · section 5
   The vacuum envelope, dee and pump arrangements, gasket practice, the gas supply system, and the protective devices that keep an operator from destroying any of it.

About this copy, and a warning about its text

This document's OCR is poor, and worse than any other copy in this collection. The original is a typescript carbon; its cover pages are unreadable noise, and even good body pages render "Nuclear Physics Laboratory" as Muclear Physies Laberatery and the section headings as near-gibberish. Treat the text layer as a search aid only. Nothing should be quoted, and no number should be taken, without reading the page image. The section titles listed above were read off the images, not off the text.

The holding library serves this document as page images and gates its download route, so this copy was assembled here from the library's IIIF image service, page by page, and given a text layer with open-source OCR in August 2026. No searchable copy was previously available. At 35 MB it exceeds the 25 MB per-file limit of the site's host, so it is served from files.cyclotroninfo.com, whole and unrecompressed.

Design rules from this document

36 Design Guide rules come from this report — construction sequence, vacuum practice, magnet model work, and, unusually, facility and building decisions, which almost nothing else here documents.

Peers in this collection: NYO-780 (Carnegie building a synchrocyclotron from scratch), ORNL-1196 (the Oak Ridge 86-inch, excavation to beam in two years) and ANL-5907 (the Argonne 60-inch). Read with TID-5215 for the magnet-model methods this report applies.