Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constraints to do realistic modeling of the electric field ahead of the
  tip of a lightning leader   Several computer models exist to explain the observation of terrestrial
gamma-ray flashes (TGFs). Some of these models estimate the electric field
ahead of lightning leaders and its effects on electron acceleration and
multiplication. In this paper, we derive a new set of constraints to do more
realistic modeling. We determine initial conditions based on in situ
measurements of electric field and vertical separation between the main charge
layers of thunderclouds. A maximum electric field strength of 50 kV/cm at sea
level is introduced as the upper constraint for the leader electric field. The
threshold for electron avalanches to develop of 2.86 kV/cm at sea level is
introduced as the lower value. With these constraints, we determine a region
where acceleration and multiplication of electrons occur. The maximum potential
difference in this region is found to be $\sim$52 MV, and the corresponding
number of avalanche multiplication lengths is $\sim$3.5. We then quantify the
effect of the ambient electric field compared to the leader field at the upper
altitude of the negative tip. Finally, we argue that only leaders with the
highest potential difference between its tips ($\sim$600 MV) can be candidates
for the production of TGFs. However, with the assumptions we have used, these
cannot explain the observed maximum energies of at least 40 MeV. Open questions
with regard to the temporal development of the streamer zone and its effect on
the shape of the electric field remain.

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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys