External Resources
The library indexes documents and the modeling-tools catalog covers software; this page maps everything else — where to watch real accelerator courses, where the professional literature lives for free, where the theses are, where to ask questions, and where the hardware actually comes from. Every entry carries an honest one-paragraph description of what a small-machine builder gets out of it.
All links on this page were verified live August 2026. A few sites block automated checking; those are marked, and are listed only where independent evidence shows they are alive. Listings are informational, not endorsements — this site has no affiliation with, and receives nothing from, anything listed here.
Video lectures & courses
Accelerator physics is one of the few fields where complete graduate courses — slides, notes, and recorded lectures — sit freely on the open web, because the field's schools publish their materials as a matter of policy.
-
Cyclotrons! — the video course (Koeth Research Group, UMD & USPAS)
The single most cyclotron-specific video resource in existence: a nine-part documentary-style course built around the Rutgers/Maryland 12-inch cyclotron, produced by the Koeth Research Group with the U.S. Particle Accelerator School. It dissects one real machine subsystem by subsystem — magnet, vacuum, ion source, RF, deflector, betatron motion and resonances, controls — at upper-level-course depth while staying watchable with any background. Watch first: Part 1, then whichever subsystem is currently on the bench. The machine itself has an entry in the builds directory.
-
USPAS course-materials archive
The U.S. Particle Accelerator School has taught intensive graduate courses since the 1980s and publishes decades of lecture notes and slide decks in a table searchable by year, subject, and instructor — everything from accelerator fundamentals to magnet engineering, RF systems, and vacuum science, courtesy of the instructors. A separate online-resources page curates free tutorials, videos, and short courses from across the field. Level: mostly graduate, but the fundamentals courses read fine with undergraduate electromagnetism. Start by searching the materials table for the fundamentals-level courses, then mine the magnet and RF courses as a build demands them.
-
CERN Accelerator School (CAS)
CERN's traveling school, running since 1983, with a previous-schools table linking each course's lecture programme and proceedings (most via the CERN Document Server; a few event pages are restricted, the proceedings generally are not). Level: graduate and professional — this is where working accelerator physicists are trained. Start with the materials of a recent "Introduction to Accelerator Physics" school and skip around; every topic a cyclotron raises has a CAS lecture.
-
CERN Academic Training lectures
CERN's in-house lecture programme, recorded since the 1990s and open to anyone with a browser — multi-lecture series on accelerator physics, RF technology, vacuum, radiation protection, and the rest of laboratory practice, delivered by the people who run the machines. The browsing site is a modern web app; the recordings themselves are archived on the CERN Document Server (and a subset on CERN's YouTube lecture channels). Broad rather than cyclotron-specific: search for the accelerator and RF series.
Conference proceedings
JACoW — the Joint Accelerator Conferences Website — is the reason accelerator engineering is one of the most openly documented fields in existence: the world's accelerator conferences publish their full proceedings there under a Creative Commons (CC BY 4.0) license, free to everyone. For a builder this matters because conference papers are where the engineering lives — magnet shimming campaigns, RF cavity fixes, ion source arc chamber geometries, commissioning war stories — written by the people who did the work, with numbers.
-
The Cyclotrons conference series
The International Conference on Cyclotrons and their Applications has met roughly every three years since 1959, and every proceedings volume is on JACoW — the single densest body of cyclotron engineering literature anywhere. The early volumes (1959–1970s) are disproportionately valuable to amateurs: they document machines at buildable scale, with design details modern papers assume away. Find the series under "Cyclotrons" on the proceedings index.
-
IPAC and the wider JACoW firehose
The International Particle Accelerator Conference publishes thousands of papers a year, and JACoW's index adds the linac, ion-source, beam-instrumentation, and regional conference series on top. Almost nothing here is about cyclotrons specifically, but when a build needs the state of the art on one narrow question — a gauge, a coating, a matching network — a JACoW search usually finds someone who measured it.
Open textbooks & lecture notes
Only genuinely free, legal sources are listed — texts the authors or publishers themselves give away. Everything else belongs in the library as a citation to obtain through normal channels.
-
Wiedemann, Particle Accelerator Physics, 4th ed.
The modern standard graduate text — roughly a thousand pages from single-particle dynamics through RF systems, synchrotron radiation, and beam instabilities — made legitimately free as an open-access book, downloadable from CERN's publishing platform. Dense and synchrotron-leaning, but the transverse-dynamics and RF chapters underpin everything a cyclotron does. A reference to own, not a first read.
-
Humphries, Principles of Charged Particle Acceleration
Stanley Humphries' classic self-study text, released free by the author on his own site. It is the most builder-friendly serious accelerator book available at no cost: it develops fields, particle dynamics, magnet design, RF acceleration, and phase stability from first principles with worked reasoning rather than citations to other textbooks, and it has a proper treatment of cyclotrons and phase dynamics. The right first accelerator textbook for a self-taught builder.
-
Tanabe, Iron Dominated Electromagnets (SLAC-R-754)
Jack Tanabe's complete course on designing exactly the kind of magnet a cyclotron uses — one whose field quality is set by pole shape and iron saturation — from field theory through pole-tip design, coil engineering, fabrication, assembly, and measurement. Written for accelerator lattice magnets, but nearly every chapter maps onto a cyclotron main magnet. The natural companion to a FEMM model and the magnet calculators.
-
CERN Document Server (CDS)
CERN's open repository: the CAS proceedings and Yellow Reports, decades of technical notes, theses, photographs, and recorded lectures, all searchable and almost all freely downloadable. When a CAS school or an Academic Training series above links "proceedings," this is where the file lives. Worth learning to search directly — the Yellow Report series on magnets, RF, and vacuum are free book-length references.
Theses collections
Student theses are the most underrated cyclotron literature: they document small machines end to end, mistakes included, at exactly the scale an amateur works. The library indexes the individual documents; these are the collections they come from.
-
Houghton University Digital Archives — Physics
Houghton's undergraduate cyclotron program has run for two decades, and its repository holds the paper trail: theses, posters, and reports covering the machine's magnet, chamber, RF, and beam work across student generations. Representative entries: Cressman, The Design and Construction of a Small Cyclotron (2006) and Fuller & Yuly, Characterizing the Houghton College Cyclotron (2012 poster). The key individual theses are indexed and rated in the library.
-
Finding theses elsewhere
Most university repositories run the same DSpace software as Houghton's, so the search pattern transfers: search a university's "institutional repository" or "electronic theses" site for cyclotron. CDS (above) holds CERN-affiliated theses; national systems such as OSTI and library catalogs cover the rest. Theses worth an amateur's time get added to the library as they are found — suggestions welcome (address at the bottom of this page).
Communities
No cyclotron-only forum currently exists. The communities below are adjacent — fusion, high voltage, electronics — but the vacuum, HV, RF, and radiation-measurement expertise transfers directly, and several have hosted cyclotron build threads. Before asking, read the starter path; when asking, post numbers. The people who have actually built machines are in the builds directory, and many are reachable through these forums.
-
Fusor.net forums
The amateur fusion community, and the strongest concentration of hands-on high voltage, vacuum, and radiation-measurement experience anywhere online. Its advanced-projects section has a long history of cyclotron build threads, and its culture of demanding measured results ("neutron club") keeps the signal high.
-
Physics Forums
The long-running general physics community (since 2001), human-moderated and homework-friendly. Best for theory questions and sanity checks on the physics side of a design; less hands-on hardware depth than the builder forums.
-
High Voltage Forum
A builder-oriented forum for Tesla coils, transformers, and general high-voltage engineering — directly useful for a cyclotron's dee supply, ion source, and deflector questions, and for the practical craft of insulation, corona control, and not getting hurt.
-
EEVblog forum
A very large electronics-engineering community. Not an accelerator forum at all, but the best place online for the supporting electronics: RF amplifier debugging, power supply design, instrumentation, and honest reviews of the used test equipment a build depends on.
-
r/Physics
Large and general-purpose — useful reach when a project writeup deserves an audience or a broad question needs many eyes, with less hands-on depth than the dedicated forums above. No active cyclotron-specific subreddit could be verified as of August 2026.
-
Guild of Cyclotron Builders (Facebook group)
The one online community dedicated specifically to cyclotron building. A private group where documented builders, students, and professionals compare magnets, RF systems, and beam results — the closest thing the hobby has to a dedicated forum.
-
Guild of Accelerator Builders (Facebook group)
The broader sibling group: amateur and professional accelerator construction of all kinds — electrostatic machines, linacs, and cyclotrons alike. Wider scope means more traffic on the shared fundamentals: ion sources, vacuum, high voltage, and beam diagnostics.
-
Beam on Target Technology Group (Facebook group)
A specialist group for what happens at the end of the beamline: targetry, isotope production, activation, and detection. Narrow, but exactly the expertise a working machine eventually needs.
-
DIY Vacuum Tubes forum
A niche community for building vacuum tubes from scratch — which makes it a concentrated source on the hard crafts a cyclotron shares with tube-making: glass-to-metal seals, feedthroughs, vacuum processing and bakeout, getters, and high-voltage conditioning of small sealed systems.
Several communities from the 2021 directory did not survive: 4hv.org and fusionforum.net were unreachable, and Coulter's science forums announce their own shutdown (checked August 2026). They are omitted rather than listed dead.
Vendors & surplus
Listings are informational, not endorsements or recommendations; this site has no affiliate or commercial relationship with any vendor. Companies were verified reachable August 2026; prices and stock are their business, not ours.
-
Ideal Vacuum Products
New and refurbished vacuum equipment — pumps, chambers, fittings, gauges, and a modular chamber system — at prices amateur projects can sometimes reach. One of the vendors most frequently named in documented hobby builds for mid-range vacuum hardware.
-
Duniway Stockroom
A longtime vacuum surplus house: rebuilt and used pumps, ion gauges, thermocouple gauges, flanges, and hardware, plus new consumables like pump oil and gaskets. The classic first stop when a build needs a working diffusion or rotary-vane pump for a fraction of the new price.
-
Kurt J. Lesker Company
The mainstream new-equipment catalog for KF and CF flanges, feedthroughs, viewports, valves, and gauging. Usually not the cheapest path, but the catalog itself doubles as a free reference — flange dimensions, material specs, and technical notes worth reading even when the parts come from eBay.
-
Surplus practice: eBay and the auction ecosystem
Most documented amateur machines were built substantially from auction surplus. Search terms that work: conflat, CF flange, KF25/NW25, turbomolecular, ion gauge, mass flow controller, RF power amplifier, and specific model numbers harvested from build reports. Ground rules: assume pumps are sold untested unless proven otherwise, budget for a rebuild, check flange sizes twice, and remember that mass flow controllers are cheap precisely because they need a controller and calibration. University and national-lab surplus auctions are the deeper end of the same pool.
-
Metals and general hardware
Magnet iron wants low-carbon steel (1006–1020); the practical sources are local steel service centers and scrapyards, where round bar and plate at cyclotron-yoke sizes are sold by weight — bring a magnet and avoid anything stainless. Copper for coils and dees comes from electrical-supply and metals distributors as bar, sheet, and refrigeration tubing. For everything else — O-rings, fasteners, brass fittings, small stock — McMaster-Carr is the field's default catalog, with usable CAD models for nearly every part.
Projects worth studying
Deeply documented projects teach what papers cannot: the order in which decisions actually got made. The first two are genuine cyclotron programs; the third is honestly adjacent — ion beam systems, not cyclotrons — and listed for its methodology.
-
Koeth Cyclotron — the Rutgers/Maryland 12-inch documentation
The most complete public documentation of an amateur-lineage cyclotron anywhere: the machine begun in a basement in the 1990s, matured at Rutgers, and now the centerpiece of a University of Maryland capstone course. The site documents every subsystem — magnet design and field measurements, the AVF conversion, chamber, vacuum, RF system and testing, three generations of ion source, electrostatic deflector, phosphor screens, controls and machine protection — plus white papers, student work, and an operator's manual. Builds-directory entries: Rutgers 12-inch, Rutgers 9-inch, and the Maryland 19-inch.
-
Nuclear Physics Lab (NPL)
The broader personal-lab site in the same lineage: accelerator pages including the cyclotron work, historical collections, and hosted papers — among them the full construction writeup of the nine-inch prototype cyclotron with drawings, one of the most reproducible small-cyclotron documents on the open web.
-
Applied Ion Systems — simulations
An open ion-propulsion project with unusually detailed public simulation writeups: Molflow models of vacuum chambers and a diffusion-pump assembly, TRIM sputtering and implantation studies, and steady-state thermal analyses of real pump hardware. None of it is a cyclotron; all of it is exactly the free-tool modeling discipline a cyclotron build needs, applied one field over — the worked-example companion to the modeling-tools catalog.
Know a resource that belongs here — alive, free where it claims to be, and useful to small-machine builders? Suggest it: [email protected]. Dead links reported to the same address get fixed.