🔬 Tokamak Fusion Reactor: Interactive 3D Cutaway

About this simulation

Tokamak Fusion Reactor: Interactive 3D Cutaway

A tokamak is a magnetic-confinement device designed to hold very hot, electrically conducting plasma away from ordinary material walls. Its signature is a toroidal, or doughnut-shaped, vacuum chamber surrounded by multiple magnetic systems. The result is one of the most intricate arrangements in experimental energy research: structural supports, current-carrying windings, vacuum boundaries, cooling hardware, diagnostic instruments, and plasma-facing surfaces all occupy the same tightly integrated machine.

This interactive exhibit presents VORTEX T-18, a fictional scientific installation made to explain that engineering. It is not a replica of a real reactor and does not describe a validated construction project. Every visible subsystem is a teaching model: the general physical ideas are authentic, but the geometry, dimensions, component placements, and animated field paths are illustrative. Visitors can orbit the assembly, cut through its external structure, isolate named components, explode them into separate systems, and assemble those systems in dependency order.

What makes a tokamak different?

A fusion experiment tries to bring light atomic nuclei sufficiently close for nuclear reactions to occur, despite their mutual electrical repulsion. That requires high-energy conditions. At the relevant temperatures, matter can become plasma: electrons are no longer bound to individual atoms, and electromagnetic fields strongly influence the motion of charged particles. No ordinary solid container can touch such a plasma without facing severe damage and cooling.

A tokamak therefore combines a vacuum enclosure with strong magnetic fields. The toroidal field runs around the long way through the ring. Other coils create poloidal components that loop through its short cross-section, helping produce twisted magnetic-field paths. Plasma current, magnetic-field shaping, particle drifts, turbulence, heating, fuelling, and exhaust all matter. A glowing torus in an animation may suggest confinement, but it cannot stand in for those interacting processes.

Tour the toroidal-field magnet array

The large D-shaped coil cases are among the most visually recognizable parts of a tokamak. In an actual superconducting installation, these structures must support enormous electromagnetic loads while protecting complicated conductor, insulation, and cryogenic systems. The coil case is not simply a decorative metal loop: it participates in mechanical force transfer, alignment, access restrictions, and assembly sequencing.

VORTEX T-18 separates each case from its copper-coloured interior winding pack. The colour is a visual convention and must not be read as evidence of a specific conductor technology. The installed array is an engineering-inspired reconstruction rather than a reproduction of a real coil cross-section. In exploded mode, moving the coils outward exposes why close spacing around the vessel makes maintenance access and installation order such difficult practical questions.

The vacuum vessel and the first wall

Inside the surrounding windings lies a toroidal vacuum boundary. A real vacuum vessel provides controlled conditions for plasma formation, allows diagnostic access through ports, and helps integrate thermal and structural systems. A vessel is neither a solid doughnut nor a completely empty tube: its interior may contain protective surfaces, components for plasma exhaust, measurement access, and substantial support hardware.

The exhibit represents the vacuum vessel using separate curved sections, with a second layer of first-wall tiles. Cutting away a front segment reveals nested geometry rather than an empty shell. The surfaces are purposefully simplified. Their thickness, texture, joints, and panel segmentation are explanatory, not an approved stress, vacuum, or radiation design. The adjustable section cut is a visualization tool and does not reproduce a physical maintenance operation.

Central solenoid: a transformer at the heart of the ring

The central solenoid sits through the centre opening of the torus. In conventional tokamak operation, changing current in this coil can induce an electric field around the plasma loop. That transformer action can help drive the plasma current. It is an important distinction: the central solenoid is not merely another toroidal-field magnet, and plasma current is not generated by placing an arbitrary glowing wire inside the vessel.

Here a mandrel, repeated winding discs, and termination leads show the solenoid's position and modular construction. Their shapes are scaled representations. The animation does not solve transformer induction, circuit coupling, current ramping, or pulse length. Those behaviours require time-dependent electromagnetic and circuit calculations using real component properties that this fictional model does not possess.

Poloidal-field coils and plasma shaping

Poloidal-field coils contribute to the magnetic configuration and allow the plasma's position and shape to be controlled. The placement of multiple coils above, below, and around the vacuum vessel is meant to reveal their different mechanical relationships with the toroidal-field array. Their operation, however, is more subtle than switching on independent circular fields.

In a real device, field control depends on coupled currents, feedback diagnostics, magnetic equilibrium, and operating constraints. The rings in the exhibit identify the principal functional category but are not sized for a chosen equilibrium. Visitors should interpret changes in the ideal field calculator as educational arithmetic, not commands that would make this exact installation operate safely or stably.

Divertor and plasma-facing engineering

A tokamak must handle particles and energy that escape the confined plasma. A divertor is a specialized region intended to manage exhaust and direct plasma interactions to surfaces designed for demanding service. It is associated with sophisticated magnetic geometry, material selection, cooling, erosion control, diagnostics, and replacement strategies.

The model's lower internal cassettes and radial cooling branches help locate this scientific function. Their shapes have been intentionally enlarged and regularized for visual inspection. They are not claims about tungsten thickness, thermal loads, plasma exhaust fraction, replacement intervals, or expected operating lifetime. Those quantities depend on an actual machine and are not inferred from the rendering.

Why the supporting infrastructure matters

The machine is more than its plasma chamber. Cryogenic service headers, insulating supports, electrical bus routing, water-cooling branches, alignment hardware, access platforms, and instrument cabinets consume significant space around the core. Even a perfectly drawn magnet cannot operate as an experimental facility without mechanical interfaces, protection systems, and reliable services.

In VORTEX T-18, technical ceramics are used as visual shorthand for insulation; stainless steel and aluminium represent structural and enclosure hardware; copper-coloured parts identify winding or conductor paths; and blue-cyan routes distinguish services. These are material categories, not certified specifications. The gallery-style maintenance platform and handrails illustrate the scale of the surrounding infrastructure without pretending to satisfy building or industrial safety codes.

Diagnostics are part of the experiment

Plasma experiments depend on measurements. Magnetic pickup coils, optical lines of sight, spectroscopy, temperature and density diagnostics, and numerous other instruments can help characterize conditions in and around the plasma. Real diagnostic systems require optical access, calibration, timing, signal processing, and protection from demanding electromagnetic and radiation environments.

The interactive model contains radial ports, diagnostic heads, magnetic pickup positions, and adjacent racks so visitors can trace a conceptual measurement pathway from the vessel to external instrumentation. These parts are engineering-inspired placements; the exhibit does not claim that a particular detector would work at a specific invented location or achieve an unstated accuracy. Selecting a component reveals its educational role rather than a fabricated product specification.

The magnetic-field calculator: an ideal toroid

The live panel uses a textbook approximation for an ideal toroidal winding: B = μ₀NI/(2πR). Here B is magnetic flux density in tesla, μ₀ is the vacuum permeability in the familiar textbook approximation, N is the illustrative effective turn count, I is the illustrative conductor current in amperes, and R is the selected ideal radius in metres. The model uses a fixed illustrative radius of 3.4 metres. This is a geometric assumption used for arithmetic, not a measured radius from a real installation.

The simplified relation assumes a suitable idealized winding geometry and neglects substantial details: discrete coil shapes, local field ripple, plasma current, ferromagnetic effects, structural deformation, and nonuniformity. As a result, the number should be called the ideal-field estimate, not the actual field everywhere in a tokamak. The current and turn sliders recalculate the estimate in the browser; they do not change the mesh or solve a self-consistent plasma equilibrium.

Gyroradius and cyclotron frequency

Charged particles curve in a magnetic field because of the Lorentz force. In a simple nonrelativistic, uniform-field picture, a proton moving perpendicular to B follows circular motion with radius r = mₚv/(eB). Its cyclotron frequency is f = eB/(2πmₚ). The panel uses a selected representative proton speed and widely used physical constants to display the illustrative radius in millimetres and frequency in megahertz.

This single-particle derivation is useful because it shows opposite dependencies: increasing magnetic field reduces gyroradius but increases cyclotron frequency, while increasing perpendicular speed increases gyroradius without changing the nonrelativistic frequency. It is not an orbit calculation for a realistic plasma population. Real ion distributions, field gradients, collisions, drifts, electric fields, and nonuniform geometry can change particle trajectories substantially.

Magnetic pressure and what it does not predict

The fourth readout follows the textbook magnetic pressure or energy-density relation p = B²/(2μ₀). The units can be expressed as pascals. This number describes a property of a magnetic field and helps explain why large magnetic installations demand serious mechanical design. It is not, on its own, a vessel-wall stress, a support load, or a prediction of confinement quality.

Calculating actual stress involves geometry, current distribution, boundary conditions, and material properties. Likewise, fusion gain, neutron yield, thermal power, cooling demand, and electricity production cannot be computed from the limited sliders provided here. Keeping those categories separate makes the simulator more scientifically honest and more useful for education.

An independent check beside the engine result

The magnetic-field panel performs a deliberately transparent numerical comparison. Its main engine evaluates μ₀NI/(2πR); an independent algebraic route replaces μ₀/(2π) with the textbook factor 2 × 10⁻⁷ in the same units. The two results are displayed alongside the numerical difference. Agreement demonstrates that the equation has been implemented consistently, within floating-point precision.

A matching check does not verify a tokamak engineering design or validate the plasma animation. It only checks arithmetic within the stated idealized model. This difference between verifying code and validating physics is fundamental whenever an interactive scientific visualization makes numerical claims.

Five views of one complex machine

Exterior mode shows the machine as a complete installation, where magnets, enclosure panels, piping, and equipment compete for space. Cutaway mode removes selected front-facing shell and vessel sectors and exposes deeper hardware. Isolate mode removes everything except a selected component. Exploded mode gives subsystems deliberate clearance for teaching their spatial relationships. Operation mode adds luminous trajectories that suggest helical magnetic structure and moving charged particles.

The animated paths are illustrative and not numerical field-line integrations from a magnetostatic solver. They should not be interpreted as experimentally measured traces. Change the camera to a three-quarter view, a front elevation, an overhead view, or a technical section. The Fit all control calculates the full geometry bounds even with the explosion set to its maximum so no subsystem is intentionally excluded from the camera framing.

Follow the guided assembly order

A highly nested scientific assembly cannot be explained well as one undifferentiated object. The guided walkthrough begins with the alignment foundation and progresses through the cryostat, vessel, toroidal coils, poloidal systems, divertor, services, and diagnostics. Each stage depends on the previous educational group. This is a comprehension sequence, not a real installation manual: the build order of an actual tokamak would reflect transportation, tooling, welding, alignment, shielding, and many site-specific constraints.

The part picker gives individual names to curved panels, coil cases, winding packs, ports, support posts, cooling paths, and racks. On a phone the settings remain in a scrollable region below the drawing surface, so the camera and Fit all controls stay accessible. Keyboard arrows orbit the model, plus and minus zoom, and the F key frames the installation.

Real science, reconstructed engineering, and fiction

The general functions of the vacuum vessel, central solenoid, toroidal-field magnets, poloidal-field coils, plasma-facing targets, and measurement systems are grounded in scientific practice. Their geometry here is engineering-inspired. The coloured field lines, particle effects, cut planes, and physical simplifications are educational representations. The named VORTEX T-18 installation and its particular arrangement are fictional.

Nothing in this page establishes facility affiliation, product compatibility, structural adequacy, cryogenic sizing, magnetic-load safety, radiation protection, or a credible plasma operating point. Every number shown by a physics control is either a textbook equation result or an illustrative assumption; the displayed 3D dimensions are scaled for understanding. Illustrative design, not affiliated with any real institution or manufacturer.

Frequently asked questions