TriToP – A compatibility experiment with turbomolecular pumps under tritium atmosphere

A turbo-molecular pump with magnetic bearing type Oerlikon Leybold MAG W 2800 has been tested under tritium atmosphere for one year with an overall throughput of about 1.3 kg of tritium (≈5 × 1018 Bq) in a closed loop. Evolution of gas composition has been regularly checked by in-line mass spectrometry. Experimental data of two long term tritium runs followed by a non-tritium run are shown. Results are discussed with regard to materials used inside the pump volume. Possible consequences for the use at the KATRIN experiment are given.

► We designed and built a new tritium test experiment for closed loop circulation with a throughput of several grams per day.
► We operated the closed tritium loop for one year with a TMP MAG W 2800 and approx. 1.3 kg tritium in total.
► We used mass spectroscopy for determination of radiation induced aging effects on non-metallic parts inside TMP.
► We see an increased production of hydrocarbons due to non-metallic parts inside the TMP pumping volume.