Behavior of separative desorption of hydrogen, helium, and methane from cryosorption pump

The behavior of dynamic desorption of He, H₂, and CH₄ from a cryosorption pump is experimentally investigated using a simplified technique to roughly purify unburned D-T fuel exhausted from a fusion reactor. As a fundamental study to dynamically separate the unburned fuel and impurities, the discharge rates of H₂ (as a representative of D₂ and T₂), He, and CH₄ (as major impurities) are determined as a function of time or temperature, when the cryosorption pump is regenerated from ∼10 K to the room temperature of 285 to 300 K according to the experimental date. It is found that H₂ is adsorbed and desorbed on active charcoal independent of the adsorption sites of He and CH₄, which are evacuated simultaneously. The present result leads to a simplified method for roughly separating unburned fuel from impurities in fusion reactors by controlling the desorption temperature.