A calorimetric probe for plasma diagnostics

Abstract

A calorimetric probe for plasma diagnostics is presented, which allows measurements of the power taken by a test substrate. The substrate can be biased and used as an electric probe in order to obtain information about the composition of the total heating power. A new calibration technique for calorimetric probes, which uses monoenergetic electrons at low pressure, has been developed for an improved accuracy. The use of the probe is exemplified with an experiment where both energetic neutral atoms and ions heat the test substrate.

The fictional transition of the preferential orientation of yttria-stabilized zirconia thin films

“…The determination of the energy flux was performed using a passive thermal probe [20]. The thermal probe was positioned in the center of the sample holder.…”

On the measurement of energy fluxes in plasmas using a calorimetric probe and a thermopile sensor

“…Details of the probe construction may be found elsewhere [18]. Although an additional copper wire connected to the plate allows for biasing, the experiments were performed at floating potential.…”

“…Since each component of the probe (thermocouple, metal plate, copper wire) has its own heat capacity the calorimetric probe has to be calibrated. The calibration of the probe is carried out with an electron beam according to a protocol developed in the IEAP Kiel [18]. For the present measurements a tungsten probe with an effective heat capacity of 281mJ/K was used.…”

“…For that, they were alternatively placed in well characterized plasma environments, e.g. in ion beam source [12,18] and in asymmetric RF discharge [14]. As we will see in the following, both sensors have drawbacks and advantages.…”

On the heating of nano- and microparticles in process plasmas

“…For a quantitative description of particle heating in plasma environment the energy fluxes have to be measured either by calorimetric probes [2,48] or by suitable microparticle probes [44]. Based on probe theory for such test particles, a calorimetric balance model can be established where the particle temperature occurs as an observable.…”