Compact generator delivers 1 T pulses lasting 3.8 microseconds using commercial ultrafast switches
A compact pulsed-magnet driver using commercial ultrafast switches produces 1 T fields in 3.8 μs, enabling single-shot magnetization and Faraday measurements on microsecond scales. The design trades peak field for speed and portability while remaining nondestructive. Future scaling to higher fields will determine whether the approach displaces larger infrastructure for ultrafast condensed-matter experiments.
The team replaced conventional high-inductance capacitor banks and slow switches with commercially available ultrafast power semiconductors, shrinking both inductance and capacitance while preserving field strength. A simple lumped-element circuit model matched the measured B(t) waveform to within a few percent, confirming that residual parasitic inductance now sets the speed limit. Magnetization loops on cobalt powder and Faraday rotation in CdS were recorded within single shots, demonstrating that the system can capture sub-microsecond dynamics without coil destruction.
Standard nondestructive pulsed magnets typically operate on 10–100 ms timescales; microsecond access has required destructive single-turn coils or large infrastructure. By achieving 3.8 μs nondestructively in a bench-top footprint, the work lowers the barrier for time-resolved studies of nonequilibrium magnetism and spin dynamics that were previously restricted to specialized facilities.
The main limitation is the modest peak field (~1 T); scaling to 5–10 T will require either higher-voltage devices or optimized coil geometry without reintroducing inductance. Parallel operation of multiple modules or superconducting boost coils are plausible next steps that could be tested within 12–18 months.
Reproducibility hinges on the availability of the specific ultrafast switches; any supply-chain change would necessitate re-validation of the rise-time performance.
Ishii et al.: within 18 months a follow-up device will exceed 5 T at <5 μs pulse width in a nondestructive coil.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2608.23584)
- [2]Supporting Source(https://doi.org/10.1063/5.0045678)