Cyclotron pedagogy design rules

Die Endenergie der Ionen ist so etwas wie die Höhe einer Leiter und die Beschleunigungsspannung ist dann der Abstand der einzelnen Sprossen [tr.: final energy is the ladder height, voltage the rung spacing]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 41-42

Editorial note, tabletop extrapolation: Recomputed for 1000 V protons at 185 mT: r1 = 24.7 mm, matching the book. A 150 keV machine at 1 kV needs 150 ideal crossings; at 5 kV only 30 - relaxing vacuum and field-error tolerance roughly in proportion. The idealization to keep visible: real voltage also moves capture, turn separation and whether the top rung is reachable at all (dg-1376's ceiling-vs-attainability).

Wir legen uns also mit einem geeigneten Detektor auf die Lauer und verändern das Magnetfeld solange, bis wir ein Signal erhalten [tr.: lie in wait with a detector and vary the field until a signal appears]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 69-71

Editorial note, tabletop extrapolation: Slow ramps help but don't grant immunity: characterize the electrometer/amplifier settling time and pick a sweep rate that resolves the narrowest expected peak - then confirm by comparing up- and down-sweeps (hysteresis and lag shift peaks in opposite directions). Correct the Hall reading to the median plane: a probe in the lid recess reads a different field than the orbit (the 1-7.5 percent class errors below), which moves every q/m assignment.

Die Deutung der anderen, kleineren Peaks [...] ist nicht immer möglich und auch nicht ganz einfach [tr.: interpreting the other smaller peaks is not always possible nor simple]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 71, 74

Editorial note, tabletop extrapolation: Keep a running peak ledger (B, f, U0, gas flow, probe radius) across runs. Persistence at fixed B across U0 and flow changes is EVIDENCE toward species/harmonic assignments, and motion is evidence toward phase-spread or direct-ion artefacts - evidence, not a classification: confirm with frequency scaling and probe-radius scans (dg-1422, dg-1425).

Physik- und Mathematik-Kenntnisse auf dem Level der 11. Klasse der Oberstufe sollten ausreichend sein [tr.: physics and maths at class-11 level should suffice]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 13

Editorial note, tabletop extrapolation: The chapter template (dialogue, then formula, then a per-subsystem results table) is a ready-made lesson structure for an educational accelerator - our reading of the book's organization, worth copying deliberately; the author's 'should suffice' keeps its hedge.

Die Herausforderung dieses Projekts bestand demnach darin, ein Zyklotron in diesem niedrigen Energiebereich zum Laufen zu bringen [tr.: the challenge was to get a cyclotron running in this low energy range]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 7-8

Editorial note, tabletop extrapolation: Define the teaching machine's safety envelope explicitly rather than declaring it hazard-free: maximum electrode potential (X-ray endpoint), ion species and energy (reaction thresholds - remembering exothermic channels like D-D have none, so deuterium is a different machine), beam current, target and contaminant composition, plus the ordinary electrical, RF, vacuum and stored-energy hazards that exist at ANY energy. Survey, don't assume; the low-energy regime shrinks the radiological terms, not the list.

Der Teilchenstrahl braucht dabei nicht einmal ausgelenkt zu werden [tr.: the particle beam does not even need to be extracted]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 27

Editorial note, tabletop extrapolation: A radial probe drive with a Faraday cup is the first detector to build on any small machine, and extraction is properly a separate later project - which, when undertaken, teaches its own lessons (septum design, transport, external diagnostics; the COLUMBUS Wien-filter plan, dg-1512, is that next chapter). Wait until internal beam is reproducible across days.

Die spezifische Ladung ist sozusagen der Personalausweis eines Teilchens. Wenn wir diese kennen, kennen wir auch das Teilchen [tr.: specific charge is a particle's identity card]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 68-69

Editorial note, tabletop extrapolation: Connecting to the e/m fine-beam tube students already know turns first beam into an assessable experiment with a literature value and a computable error - the PROTON value being 9.58e7 C/kg. Teach the degeneracy honestly: q/m alone does not name the particle (D+, H2+ and He2+ all sit near 4.8e7 C/kg), so the identity card needs the source-gas and charge-state context too (dg-1422's candidate discipline).

Sicher hätte sich das Projekt nicht gelohnt, wenn es nach dem erfolgreichen Abschluss im Jahre 2014 beendet worden wäre [tr.: the project would not have been worth it had it ended in 2014]

Prechtl & Wolf, Das Lehr-Zyklotron COLUMBUS — Mit einem Teilchenbeschleuniger Physik und Technik erleben, Springer (2020) — p. 75-76

Editorial note, tabletop extrapolation: The listed follow-on improvements (magnet stand, acceleration simulation, probe translator, mechanical model) are the kind of second-year items a small-machine program should schedule rather than improvise - as this case study's pattern, adapted to local aims, not a universal checklist.

After the FZ Juelich provided a magnet, VACOM, a company for vacuum components, sponsored a suitable vacuum chamber ... the cyclotron COLUMBUS began in 2012. ... The first beam was registered in April 2014 (see Fig. 2), which was followed by the first workshop with students in autumn of the same year. ... The COLUMBUS project, started in 2012, has developed very positively in the last 10 years.

Wolf & Prechtl, COLUMBUS — A Small Cyclotron for School and Teaching Purposes — THPO001, Proceedings of Cyclotrons2022 (2022) — p. 1

Editorial note, tabletop extrapolation: A realistic schedule anchor for the plan's teaching-machine ambitions: two years start-to-beam WITH a donated magnet and sponsored chamber - the in-kind support is part of the datum. And the methodological point stands: a conference paper's year dates the claim; prefer the builders' own retrospective dates when reconstructing a machine's history.

the detector is set to a specific position and the magnetic field is continuously increased. With very specific magnetic fields, there are peaks in the beam current

Wolf & Prechtl, COLUMBUS — A Small Cyclotron for School and Teaching Purposes — THPO001, Proceedings of Cyclotrons2022 (2022) — p. 2

Editorial note, tabletop extrapolation: A B-sweep at fixed frequency is a q/m RESONANCE SURVEY - the cheapest species diagnostic a small machine has, not a full mass spectrometer: state the harmonic number, calibrate the field reading (dg-1428), and resolve the q/m degeneracies and harmonic ambiguities by field-ratio checks or frequency scaling (dg-1422/dg-1423) before naming species.

The aim of this project is to deflect the ion beam and guide it through a Wien Filter to measure the speed and energy of the ions.

Wolf & Prechtl, COLUMBUS — A Small Cyclotron for School and Teaching Purposes — THPO001, Proceedings of Cyclotrons2022 (2022) — p. 3

Editorial note, tabletop extrapolation: A Wien filter is a realistic first external beamline element for a low-energy machine: it measures VELOCITY directly and yields energy only once the species is known (or paired with a separate analyzer) - which is exactly why it also cross-checks species assignments. It needs crossed electric AND magnetic fields; at keV energies both are modest, but 'electrostatic-only' it is not.

The cyclotron was continuously improved and expanded with the involvement of pupils and students.

Wolf & Prechtl, COLUMBUS — A Small Cyclotron for School and Teaching Purposes — THPO001, Proceedings of Cyclotrons2022 (2022) — p. 1

Editorial note, tabletop extrapolation: An educational machine CAN make learner projects its upgrade workforce when they are scoped as real subsystem work - a Faraday-cup translator or a field map is simultaneously curriculum and infrastructure; whether that is the fastest improvement route is a program-design judgment, not this paper's measurement.

A workshop takes place in groups with up to 6 participants. If more people register, up to 12 persons can be accepted, who will then be divided into two groups.

Wolf & Prechtl, COLUMBUS — A Small Cyclotron for School and Teaching Purposes — THPO001, Proceedings of Cyclotrons2022 (2022) — p. 2

Editorial note, tabletop extrapolation: Six-per-group is the format the team settled on for one machine - a reasonable planning anchor for hands-on accelerator teaching, not a demonstrated pedagogical ceiling; whether hybrid delivery preserves learning quality is an outcomes question the paper doesn't measure. Copy the structure, evaluate your own.

In order to build such a small cyclotron one has to meet two conditions: Vacuum, magnetic field, frequency etc. must be so low that one can use standard components as far as possible, otherwise the costs will go to infinity; The final energy of the cyclotron must be small enough so that no harmful radiation can arise, so that the students can do experiments with the cyclotron. Table 1 shows the technical data of COLUMBUS. One can easily recognize that COLUMBUS meets all the conditions mentioned above.

Wolf, Frank & Held, COLUMBUS — A Small Cyclotron for School and Teaching Purposes — WE1PB03, Proceedings of Cyclotrons2013 (2013) — p. 1

Editorial note, tabletop extrapolation: A hobby-scale build benefits from the same requirements discipline; writing the cost condition and the radiation condition down first turns every later component choice into a check against them. The radiation condition itself needs its own verification, not just an energy number: whether 'no harmful radiation can arise' at a given operating point is the paper's claim for its machine, and X-rays begin when high voltage or RF is energized, before any beam.

As shown in Fig. 1 the simulation consists of three sections, the input-layer, the simulation-layer and the presentation-layer. … The input-layer incorporates three groups of parameters which define the ions, the experiment and the geometry of the cyclotron. So the simulation can be easily adapted to different situations. … The simulation engine described above has three modules for the evaluation: XY-Plot, Intensity-Plot and Spectrometer-Plot. Every module - apart from the graphical output - allows also a data export to a file so that the measured values can be processed by external programs.

Wolf, Rueß & Prechtl, Simulation and Detection of the Helical Ion-Paths in a Small Cyclotron — MOB02, Proceedings of Cyclotrons2016 (2016) — p. 1, 2

Editorial note, tabletop extrapolation: Separating ion, experiment, and geometry parameter groups lets one code serve several machine configurations and several experiments; the data-export hook is what allows direct overlay of simulated and measured detector scans.

In this experiment the beam is measured in dependence of the magnetic field at a fixed position of the detector. Here one can identify the ions in the beam … The Spectrometer-Plot (Fig. 8) shows the caluculated probability as a measure for the beam-current vs. the magnetic field and allows to simulate this experiment.

Wolf, Rueß & Prechtl, Simulation and Detection of the Helical Ion-Paths in a Small Cyclotron — MOB02, Proceedings of Cyclotrons2016 (2016) — p. 3

Editorial note, tabletop extrapolation: A fixed-cup B-sweep is a species diagnostic using hardware a small hydrogen machine already carries, separating proton from molecular-ion contributions; simulating the sweep first tells the operator which peak to expect where. The assignment rests on rigidity plus the assumed charge and energy, so overlapping peaks can stay ambiguous.