Research on Broad-Spectrum Sterilization Capability of High Voltage Power Supplies for Irradiation Applications
As a representative non-thermal physical sterilization technology, irradiation sterilization relies fundamentally on the performance of high-voltage power supplies to achieve broad-spectrum microbial inactivation. This study systematically examines the universal effectiveness against bacteria, fungi, and viruses through the lens of power supply engineering.
1. Physicochemical Basis of Broad-Spectrum Sterilization
High-voltage power supplies drive electron accelerators to generate 0.5-10MeV electron beams or maintain stable γ-ray fields, inducing DNA/RNA strand breaks and protein denaturation. This process demonstrates equivalent efficacy against Gram-negative bacteria (e.g., E. coli), spores (e.g., Bacillus anthracis), and non-enveloped viruses (e.g., norovirus). Experimental data show 6-8 log reductions in microbial viability at 25kGy irradiation doses.
2. Technical Adaptability of High Voltage Systems
1. Energy Spectrum Modulation
Multistage Marx generators with pulse-forming networks enable precise adjustment of electron beam energy within 0.1-20ms pulse widths. This wide-range output allows deep penetration (20cm frozen meat for Listeria inactivation) and surface treatment (nut products for Salmonella elimination).
2. Dynamic Load Compensation
FPGA-based digital control modules maintain beam current stability within ±0.5% under 0-100% sudden load variations, adapting to media densities ranging from 4.5g/cm³ (seafood) to 0.3g/cm³ (puffed snacks).
3. Hybrid Waveform Output
Overlapping pulse sequences with DC bias enable simultaneous deep sterilization (high-voltage pulses) and surface passivation (low-voltage sustainment), crucial for fresh produce with complex microbiomes.
3. Application Scenario Analysis
| Field | Target Microorganisms | Power Parameters | Inactivation Efficiency |
|------------------|---------------------------|------------------------|-------------------------|
| Medical Devices | Thermophilic spores, Prions | 5MeV/200kW/CW mode | ≥10⁶ reduction |
| Seasonings | Mold spores, Halophiles | 3MeV/Pulsed 50Hz | ≥99.9% |
| Cold Chain | Listeria, Pseudomonas | ±5% dynamic regulation | 5-log reduction |
Data sources:
4. Critical Parameters for Broad-Spectrum Performance
1. Dose Uniformity: Scanning magnets and beam broadening achieve product dose uniformity ratios <1.15
2. Penetration Depth: 10MeV electrons attain 4.3cm half-value layer in polyethylene
3. Thermal Management: Recirculating liquid cooling limits temperature rise to ≤2℃/h
5. Future Directions
Emerging technologies focus on: ①AI-powered dose prediction models for pathogen-specific energy delivery; ②SiC-based solid-state modulators improving conversion efficiency beyond 92%; ③Programmable electric field topologies for nanoscale pathogen inactivation.