Institute of Plasma Physics, Czech Academy of Sciences (IPP CAS)

From COMPASS to COMPASS-U: Czech IPP’s research history, high-field tokamak design and STEAM heat-exhaust tests, with results distinguished from design goals.

Official company website ↗Read the Japanese original

CURRENT STATUS

COMPASS-U construction and STEAM development

Information checked: 2026-10-30

COUNTRY: Czech Republic
TECHNOLOGY: Tokamak physics, plasma exhaust and materials testing
FOUNDED: Not verified
FUNDING: Not verified

DEVELOPMENT ROADMAP

CONCEPTConcept

DESIGNDesign

CONSTRUCTIONConstruction

FIRST PLASMAFirst plasma

NET ENERGYEnergy gain

PILOT PLANTDemonstration plant

COMMERCIALCommercial operation

This is a general development-stage reference. This company's or project's precise stage is unconfirmed, so no position is assigned. Development pathways vary by technology and business.

The Czech institute is not Germany’s IPP

The Institute of Plasma Physics of the Czech Academy of Sciences (IPP CAS), based in Prague, is a public research institute distinct from the Max Planck institute with the same acronym. It celebrated its sixtieth anniversary in 2019. Its remit includes fusion plasma, laser plasma, plasma chemistry and materials, and precision optics.

In fusion, experiments, theory and engineering contribute knowledge and diagnostic technologies to larger European programs. A domestic experimental facility enables researchers to connect design, operation and interpretation. The institute, the COMPASS-U machine and future generating-reactor concepts are different entities and should not be counted interchangeably.

From COMPASS to COMPASS-U

The former COMPASS was transferred from the UK and achieved first plasma in Prague on 9 December 2008. Scientific exploitation and high-confinement-mode research developed in 2012; its final experimental discharge took place on 20 August 2021. Historical results must not be presented as evidence that the old machine remains operational.

The successor COMPASS-U project began in 2017. Its combination of high magnetic field, metallic surfaces, elevated wall temperature and flexible divertor geometry is intended to inform ITER operation and future reactor design. Figures such as 5 tesla and 2 megaamperes in the official specification are design parameters, not achieved experimental records.

Its magnet design also matters: COMPASS-U specifies cooled copper-based conductors, so high field does not imply superconducting coils. Resistive heating and cooling between discharges affect operation. A field specification cannot be read as achievement of long-duration continuous operation, and pulse duration is distinct from repetition capability.

Engineering the heat exit

A divertor receives heat and particles leaving along magnetic field lines. COMPASS-U combines plans for a closed divertor, dense boundary plasma and tungsten-based metallic surfaces. Its nominal 300°C wall condition describes material-side operation, not core plasma temperature.

Protecting a small target area requires dispersing energy before plasma reaches the surface, including through detached conditions. A more heat-resistant material alone is not a complete solution. Exhaust control must coexist with core confinement and resilience to sudden loads. The research mission therefore includes comparisons of operating regimes, disruptions and runaway electrons.

What the 2026 cooling test establishes

An institute announcement dated 27 October 2026 described STEAM cooling developed with the Czech Academy’s Institute of Thermomechanics and the Czech Technical University. The approach uses a lamellar surface, water boiling and steam removal. A vacuum-tight prototype reportedly showed no visible damage after a plasma-torch exposure of 100 MW/m² for two minutes.

That figure is heat flux, not electrical output. A heated prototype test does not establish performance under a reactor’s combined neutron irradiation, repeated loading, corrosion and maintenance conditions. The announcement also does not claim direct confirmation of the proposed suppression mechanism for critical heat flux. The achieved exposure and remaining validation must therefore be kept separate.

Industrial relevance and outstanding validation

IPP CAS contributes comparisons of plasma conditions, heat-load mitigation, diagnostics, control and engineering validation rather than selling a complete reactor. Precision manufacturing, vacuum components, power supplies and cooling are relevant industrial capabilities, but their relevance alone is not evidence of a particular supplier contract.

For COMPASS-U, design, manufacture, integration and operation are distinct milestones. First plasma and achievement of target conditions require their own official evidence. Scaling knowledge to larger reactors also requires accounting for different dimensions, exposure durations and material environments. Separating COMPASS operating experience, COMPASS-U design objectives and cooling-prototype results makes the institute’s contribution clearer.

Sources

Sources reviewed：2026-10-30

Companies DATA

Country: Czech Republic
Region: Europe
Company category: Public research institute
Approach / reactor type: Tokamak physics, plasma exhaust and materials testing
Development stage: COMPASS-U construction and STEAM development

Check the official information

Sources and primary documents

Checked：2026-10-30