Cryopump Thermal Radiation & Heat Load Calculator
Calculate 80K thermal radiation shield load, 15K second-stage cryo-array heat load, and gas condensation duty per ISO/ASTM cryopumping standards.
Shield & Stage Geometry
Thermal Heat Loads (Watts)
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
Why are cryopumps constructed with two distinct cooling stages?
The 1st stage (60K–80K) condenses water vapor and carbon dioxide and acts as an optical radiation shield. This protects the 2nd stage (10K–15K), which has much lower cooling capacity (1–5 W) and condenses nitrogen, argon, and cryosorbs hydrogen/helium.
How does baffle emissivity affect cryocooler load?
Stefan-Boltzmann thermal radiation scales with T⁴. At 300K, blackbody radiation is ~460 W/m². Polished, low-emissivity (ε < 0.1) baffles reject over 90% of this heat load.
What happens when the 15K second stage gets overloaded?
If thermal radiation or condensing gas heat exceeds the second-stage refrigerator capacity, array temperature rises above 20K, causing catastrophic thermal desorption of stored hydrogen and helium.