Linear plasma device GyM for plasma-material interaction studies

GyM is a linear plasma device operating at Istituto per la Scienza e Tecnologia dei Plasmi, Consiglio Nazionale delle Ricerche, Milan, with the original aim of studying basic physics, such as turbulent processes. Since 2014, experimental program has been mainly focused on issue plasma-material interaction (PMI) for magnetic confinement nuclear fusion applications. consists stainless steel vacuum chamber (radius and length 0.125 m 2.11 m), pumping system, gas injection 10 field coils two magnetron sources 2.45 GHz, capable delivering total microwave power up to 4.5 kW. Highly reproducible steady-state plasmas different species, maximum working pressure ∼10−1 Pa, can be obtained by electron cyclotron resonance heating in layer 87.5 mT. Plasmas have ion temperature ≤15 eV ∼0.1 eV, respectively. The density range 15 –10 17 −3 flux ≤5 × 20 ions⋅m −2 s −1 . Main diagnostics comprise Langmuir probes, an optical emission spectrometer, mass spectrometer fast camera system equipped image intensifier unit. For purpose investigating topic PMI, provided sample exposure systems. Both are biasable negative bias voltage down −400 V, tune energy impinging ions. One them also lamp reach sustain 990 K several hours, thus allowing study role during interaction. This contribution presents layout GyM, diagnostics, systems typical parameters. A brief overview main PMI activities carried out so far description future machine upgrades given.