Construction Classics
The construction-era cyclotron reports — AEC laboratory documents from the 1940s and 1950s that record how real machines were designed, fabricated, and commissioned — survive today as scans scattered across OSTI, DTIC, and archive mirrors. Any of those copies can move or vanish. This collection hosts the ones that are public domain, so the documents the Design Guide extracts its rules from stay readable at a stable address.
Each document gets its own page with a full citation, the hosted PDF, a public-domain rationale stating exactly why hosting is lawful, a reading guide keyed to the report’s own page numbers, and links to the design rules extracted from it. Nothing is hosted without a documented rights basis; the copyrighted majority of the library remains cite-only.
The shelf is no longer only construction reports. Since October 2026 it also carries the public-domain measurement and standards documents behind the Design Guide’s rules on kilovolt X-ray output, electrons in gas and the hot-filament ion source, some of them journal papers older than the cyclotron itself. The same rights test applies to each, and the documents from the same mining waves that failed it are named on the cluster pages with the reason.
One reading rule for the whole shelf. These reports are the record of how the method was worked out, and the method is what transfers; the tooling often does not. Where a report builds a scale-model magnet, a fractional-scale RF system or an analogue machine before committing to metal, that was the only way in its decade to see the answer first — a builder today gets the same answer from a free field solver or an orbit code before any model is built, and the modelling-tools page names them. Where a report’s vacuum plant, electronics, instruments or dose limits have since been superseded, the reading guide says so in place. The physics, the formulas and the measured comparisons between prediction and the real machine are what to read these for.
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Electrons in gas — four documents, 1922–1970
What happens to electrons that travel through gas rather than vacuum. Johnson focuses a 300-volt beam with a trace of argon and explains why by ion space charge; Brode measures how strongly each gas removes slow electrons from a beam; Berger and Seltzer tabulate range and X-ray yield from 10 keV up; a Langley wind-tunnel team puts a spectrograph on the glow of a 26 keV beam and finds trace nitrogen doing most of the shining.
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Hot-filament arc sources — five documents, 1925–1954
The component most small cyclotrons share, from three directions. Two 1925 Physical Review papers settle which hydrogen ions an electron-impact discharge makes and which knobs shift the mix; two Oak Ridge calutron reports weigh filaments to find out why they die and show a four-light-bulb ballast that doubles their life; the Ohio State final report writes down the procedure for positioning a filament while watching the beam.
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R.F. System for Frequency Modulated Cyclotron
The RF system of the first synchrocyclotron — the Berkeley 37-inch FM conversion — at amateur scale: one dee, 5 kW, commercial triodes, and a worked phase-correction analysis.
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The 184-inch Commissioning Papers, 1946–47
Six declassified memos from the 184-inch’s first year: the beam that stopped at 82 inches, the experiments that found out why, and the fixes that failed — raw commissioning logs, the scarcest content class.
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Character of the Radiation Field and Shielding at the 184-Inch Cyclotron
The collection’s first MEASURED shielding source rather than a method: half-value thicknesses for six materials taken with the cyclotron itself as the neutron source, the composite-layer result that paraffin behind lead doubles the reading, and a dose map normalised to beam current. B. J. Moyer later gave his name to the Moyer model.
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Design of the Radio-Frequency System for the 184-inch Cyclotron
The design history of the 184-inch RF system by the four engineers who built it, written so that "others designing frequency-modulated oscillators" could reuse the reasoning.
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Beam extraction hardware — four reports, 1948–1963
Fifteen years of Berkeley answering the hardest question in a small build four ways: a sixteen-thyratron deflector pulser, regenerative extraction theory, RF-driven extraction, and a supply that limits the energy of each spark rather than trying to prevent it.
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Knowing before building — four reports, 1947 and 1961
One question answered two ways fourteen years apart. The 1947 pair is a proposal and its verification three months later: MacKenzie sets out the “three quarter wave” RF system, then Anderson reports the half-scale model tests of it. Plus two 1961 MSU computations — resonant-extraction optics by orbit tracking, and analytic dee field formulas that are size-independent.
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General Recommendations for Design of Small Cyclotrons
The only report written for someone about to build a small cyclotron — a design cookbook with a working 6-inch machine as the example.
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Magnets and Magnetic Measuring Techniques
A 226-page AEC volume about magnets and nothing else, from the laboratory that had built more cyclotron magnets than anywhere on earth. Four chapters: design requirements, measuring instruments and technique, MODEL magnets and their performance, and tests on full-scale magnets. The model-magnet chapter answers a question this collection had been chasing through undigitised reports.
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Design and Construction of Synchro-Cyclotron
One institution building one synchrocyclotron from scratch — model magnets, coil winding, leak testing, oscillator debugging, shielding — in a single final report.
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The University of Washington 60-Inch Cyclotron
A construction record, the scarcest class here: a 60-inch machine for 20 MeV deuterons, documented from buildings through magnet to vacuum system. Built deliberately from Berkeley’s Crocker cyclotron drawings, supplied by E. O. Lawrence — a documented case of copying a machine known to work rather than originating a design. Half its concrete building is buried.
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Cyclotron Component Design Technical Reports
The engineering behind NYO-780, under the same ONR contract: seven technical reports on magnets, vacuum, frequency modulation, RF and extraction timing — including the collection’s only cost-minimised magnet design, optimised against the unit cost of steel, copper and ten-year energy.
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The 22-inch test cyclotron — seven reports, 1951–1955
Consecutive progress reports following ONE small cyclotron for three and a quarter years — first resolved proton orbits, a rename from 22-inch to 44-inch when the magnet was reworked, a rebuild for 100 kV dees and dual-radius running, then assembly. Includes the contractor’s brazing errors and the funding delays.
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The Oak Ridge 86-Inch Cyclotron
The most complete construction-and-commissioning record in the open literature: excavation to milliampere beams in two years, every subsystem documented and costed.
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Targets and the target plane — three reports, 1952–1961
The target plane end to end: a bench recipe for self-supporting boron and magnesium films at tens of µg/cm², and two methods for measuring the beam that hits them — including the finding that internal beam energy can sit ±10% off the value calculated from field and radius.
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Commissioning Practice — three reports, 1952–1966
What happens after first assembly: two consecutive Oak Ridge quarterlies logging three cyclotrons commissioned side by side — including a 63-inch holding 75 kV dee-to-dee against a 60 kV design — plus a study of retrofitting an axial ion source into a working machine.
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Studies with a Three-Dee Three-Phase Proton Cyclotron
The closest size match the repository searches have found: a 20-inch machine built around a magnet that was already available, where moving the ion source off centre doubled the beam and two independent current measurements were made to disagree in public.
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RF Power Engineering — four reports, 1955–1965
How to drive the dees, from three directions: a three-phase system for three-dee machines, an argument that the accelerating waveform should be a square wave rather than a sine, and a power amplifier rebuilt around a ceramic tetrode.
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Residual radiation and personnel dose — two reports, 1958–1961
What a running cyclotron leaves behind, measured rather than estimated: the activation products a machine structure becomes, nuclide by nuclide and alloy by alloy, and five years of film-badge dose for the crew who had to walk up to the target.
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The Rochester 27-inch — five reports, 1954–1962
One 27-inch university machine across eight years, both halves of its life. Two machine reports — a spark gap that starts an oscillator stuck below its multipactor band, and a hooded arc source that makes more ions from less filament — and three on what came after: external-beam focusing and analysis, a broad-range spectrograph, and fast-neutron time-of-flight. The same laboratory that published a spectrograph also had to publish a note about a spark gap.
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The Oak Ridge Relativistic Isochronous Cyclotron
The ORIC design study by Blosser, Cohen, Gordon, and Welton — the report that established the model-magnet method behind every modern AVF cyclotron.
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Cyclotrons and High-Energy Accelerators — 1958
The 1958 world accelerator census: standardized magnet, RF, vacuum, and beam data sheets for 140 machines — what everyone else chose, in one public-domain volume.
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The Argonne 60-Inch Cyclotron
A terse system-by-system record of a mature workhorse, with acceptance specs, measured tolerances, and the collection’s only suppliers-and-fabricators list.
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X-ray output below 100 kV — four documents, 1961–1978
How many X-rays an evacuated gap with kilovolts across it makes, measured. A 1970 federal survey of classroom discharge tubes, including the ones not meant to emit, read at 1 to 16 ft; a 1978 compendium of tungsten-tube output and spectra at 20–60 kVp; the 1961 handbook that wrote down the barrier equation and the lead transmission curves behind it; and the 1972 analytical-equipment standard on gassy rectifiers, pinhole leaks and meters that read low.
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Electrical Design of Electrostatic Deflectors for Sector-Focused Cyclotrons
The measured basis for beam extraction — long the thinnest subject in this collection, and the report that started closing it. Electrode materials ranked by spark damage, the VE relationship, a stated design derating, and the tungsten-versus-carbon septum trade, all from the 88-Inch Cyclotron.
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A Proposal for the Mc² Isochronous Cyclotron
A complete engineering design for a machine never built: an 810 MeV eight-sector isochronous cyclotron, worked to construction standard across fourteen chapters — including shielding, costs and schedule, the sections almost no accelerator document contains.
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Operations records — two reports, 1964 and 1970
Two machines being run rather than built. NRL accounts for every hour of six months: 60.1% operating, and power supplies and vacuum together taking twelve times more time than the RF. Harvard opens on four days lost to a cold-trap refrigerator and low diffusion-pump oil. Nobody writes an operations report to be instructive, which is what makes them worth reading.
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Accelerator Radiation Protection
Written to support drafting an Army regulation, and scoped to accelerators below 40–50 MeV — the only document here whose energy range starts where a small machine sits. X-ray and neutron shielding, induced radioactivity, exposure limits, pulsed-beam measurement, interlocks. Five figures borrowed from McGraw-Hill and ASME are replaced by notice pages.
In the queue
The August 2026 repository hunt verified open public copies of these further construction reports at the links below. Restoration and hosting here follows as rights are stamped — each needs the same documented public-domain determination as the hosted set, and two (the 1939 Simon dissertation and UCRL-8767) may not clear, both for the same reason: a thesis stays its author’s copyright. Until then, the source-repository copies are the reference.
- Zucker, Fowler & Livingston, Status Report on the 63" Cyclotron Heavy Particle Accelerator, CF-51-5-182, ORNL, 1951 — Construction status of the ORNL 63-inch heavy-particle machine. [OSTI]
- Fulbright, Bromley et al., Preliminary Report on the New 8 MeV Variable Energy Cyclotron of the University of Rochester, NYO-6541, 1954 — Short machine-design report from a first-rank builder group. [OSTI]
- Howard (ed.), Notes on an Azimuthally Varying Field (AVF) Cyclotron, CF-56-3-112, ORNL, 1956 — Design notes at the birth of the AVF era at ORNL. [OSTI]
- Livingston, Howard & Rudolph, Bibliography of Cyclotron Literature, ORNL-2023, 1956 — The period’s own index of construction reports — the map for the next recovery pass. [OSTI]
- Parkinson & Tickle, The University of Michigan 83-inch Cyclotron, Final Report, COO-921-16, 1965 — Project final report on the 83-inch construction. [OSTI]
- Simon, The Generation of Radio-Frequency Power for a Cyclotron, Ph.D. dissertation, University of Chicago, 1939 — Pre-war RF power engineering for the Chicago cyclotron. Rights determination pending — a 1939 dissertation needs a renewal search before hosting. [archive.org]
- Brown, Beam-Profile Indicator for 184-Inch Cyclotron, UCRL-8767, 1959 — A plastic-scintillator and camera beam-profile monitor — cheap and reproducible. Rights determination pending: the catalogue record marks it a thesis, and a thesis stays its author’s copyright even when the artifact carries a laboratory report number. [OSTI]
- Space Radiation Effects Laboratory, NASA, 1962 (NTRS 19650011873) — Facility design description for the NASA 600 MeV synchrocyclotron at project outset. [NTRS]
- SREL User’s Handbook, NASA, 1969 (NTRS 20040075026) — Machine properties, beam parameters, and facilities of the 600 MeV synchrocyclotron. [NTRS]
Twenty-nine entries hosting sixty-nine public-domain PDFs is the honest current size of this collection, not its intended limit. It grows only as rights clear: candidates with unverified renewal status stay in the queue, and at least one classic paper enters the US public domain in 2029. Rights determinations are dated on each document page.