Plasma instability of a vacuum arc centrifuge.

نویسندگان

  • M J Hole
  • R S Dallaqua
  • S W Simpson
  • E Del Bosco
چکیده

Ever since conception of the vacuum arc centrifuge in 1980, periodic fluctuations in the ion saturation current and floating potential have been observed in Langmuir probe measurements in the rotation region of a vacuum arc centrifuge. In this work we develop a linearized theoretical model to describe a range of instabilities in the vacuum arc centrifuge plasma column, and then test the validity of the description through comparison with experiment. We conclude that the observed instability is a "universal" instability, driven by the density gradient, in a plasma with finite conductivity.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Chopping effect observed at cathodic arc initiation

Chopping of current and induction of high voltage spikes has been observed at the rising edge of cathodic vacuum arcs. It is argued that current chopping at the rising edge is similar to the current chopping effect that is well-know for the arc current approaching current-zero. Current chopping can generate high voltage spikes, and thus cathodic arc equipment should be protected against voltage...

متن کامل

Wave-driven countercurrent plasma centrifuge

A method for driving rotation and a countercurrent flow in a fully ionized plasma centrifuge is described. The rotation is produced by radiofrequency waves near the cyclotron resonance. The wave energy is transferred into potential energy in a manner similar to the α channeling effect. The countercurrent flow may also be driven by radiofrequency waves. By driving both the rotation and the flow ...

متن کامل

Method and apparatus for automatically re-igniting vacuum arc plasma source

An apparatus and method are disclosed whereby if the arc in a DC or long-pulse AC vacuum arc plasma process (eg in vacuum deposition) starts to extinguish, this is automatically detected and a reignition process is activated. Detection of a tendency for the arc to extinguish is detected by monitoring the main power supply voltage, which will increase if the arc is extinguished. References Cited...

متن کامل

Laboratory evidence for stochastic plasma-wave growth.

The first laboratory confirmation of stochastic growth theory is reported. Floating potential fluctuations are measured in a vacuum arc centrifuge using a Langmuir probe. Statistical analysis of the energy density reveals a lognormal distribution over roughly 2 orders of magnitude, with a high-field nonlinear cutoff whose spatial dependence is consistent with the predicted eigenmode profile. Th...

متن کامل

Axial ion charge state distribution in the vacuum arc plasma jet

We report on our experimental studies of the ion charge state distribution ~CSD! of vacuum arc plasmas using a time-of-flight diagnostic method. The dependence of the CSD on the axial distance from the plasma source region was measured for a titanium vacuum arc. It was found that the axial CSD profile is nonuniform. Generally, the mean charge state increases approximately linearly with axial di...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Physical review. E, Statistical, nonlinear, and soft matter physics

دوره 65 4 Pt 2B  شماره 

صفحات  -

تاریخ انتشار 2002