Spatially resolved probe measurements in hydrogen rf discharges
Authors | |
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Year of publication | 2005 |
Type | Article in Proceedings |
Conference | Proceedings of the 14th Annual Conference of Doctoral Students - WDS 2005 |
MU Faculty or unit | |
Citation | |
Field | Plasma physics |
Keywords | plasma hydrogen discharge Langmuir probe |
Description | The electron energy distribution (EED) was measured by means of the Langmuir probe in hydrogen capacitively coupled rf discharge at three different pressures (2.5, 10 and 85\,Pa). In order to obtain the spatially resolved EEDs the probe tip was moved along the discharge axis and the plasma parameters were measured at different distances from the electrodes. An unusually high electron energy at the lowest pressure was observed having its maximum at the sheath edge, where the maximum of the electron concentration was also located. On the other hand, at higher pressures the electron concentration was maximum inside the plasma bulk. When the pressure was increased, the increase of the electron concentration, decrease of the mean electron energy, changes of the nonlocal discharge character towards the local character and the development of the sheath at the grounded electrode were observed. A high-energy group of electrons coming from the sheaths at the highest pressure was detected. |
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