SXR Measurements in INTI PF Operated in Neon to Identify Typical (Normal N) Profile for Shots with Good Yield
The six-phase Lee model code was developed to compute the anomalous resistance phase (RAN) following the pinch phase in a plasma focus (PF) discharge. One important method to check such modeling is to look at the soft X-ray (SXR) emission time profile and to correlate this to the PF dynamics. A...
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Main Authors: | , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
IEEE
2013
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Subjects: | |
Online Access: | http://eprints.intimal.edu.my/176/1/SXR%20measurements%20in%20INTI%20PF%20operated%20in%20neon%20to%20identify%20typical%20%28normal%20n%29%20profile%20for%20shots%20with%20good%20yield.pdf http://eprints.intimal.edu.my/176/ |
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Institution: | INTI International University |
Language: | English |
Summary: | The six-phase Lee model code was developed to
compute the anomalous resistance phase (RAN) following the
pinch phase in a plasma focus (PF) discharge. One important
method to check such modeling is to look at the soft X-ray
(SXR) emission time profile and to correlate this to the PF
dynamics. A two-channel filtered SXR spectrometer coupled with
an Excel-based analytical template was recently developed to
speed up the correlation process. Using this system, we have
determined that the neon PF typically operates in a normal (N)
mode in which it emits characteristic He-like H-like neon line
SXR (in a photon energy window of 900–1550 eV) reproducibly
and efficiently. The characteristic neon line SXR pulse straddles
the pinch duration starting strongly 10 ns before the start of
the pinch, then diminishes through the 10-ns pinch and tails off
into the subsequent RAN1 phase. We present the correlated time
profiles of shots operating in the efficient N mode as well as, for
comparison, poor shots, which are distinctly different in SXR
time profiles. The profiles indicate the difference in dynamics
of normal and poor shots. Statistics are presented as well as
comparison of the yields from the numerical experiments and
measurements. In the series that were studied the proportion
of N-mode operation ranges from 70% in one series to 80% in
another series over pressure range 1–4 torr. At 2 torr, it was found
that 90% recorded the normal N profile. The results reinforce
the view that while the Lee Model code incorporates the correct
physics in its sequence of phases, refinement is needed to extend
the radiative phase to the period before the pinch. |
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