Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electrostatic shielding versus anode-proximity effect in large area
  field emitters   Field emisison of electrons crucially depends on the enhancement of the local
electric field around nanotips. The enhancement is maximum when individual
emitter-tips are well separated. As the distance between two or more nanotips
decreases, the field enhancement at individual tips reduces due to the
shielding effect. The anode-proximity effect acts in quite the opposite way,
increasing the local field as the anode is brought closer to the emitter. For
isolated emitters, this effect is pronounced when the anode is at a distance
less than three times the height of the emitter. It is shown here that for a
large area field emitter (LAFE), the anode proximity effect increases
dramatically and can counterbalance shielding effects to a large extent. Also,
it is significant even when the anode is far away. The apex field enhancement
factor for a LAFE in the presence of an anode is derived using the line charge
model. It is found to explain the observations well and can accurately predict
the apex enhancement factors. The results are supported by numerical studies
using COMSOL Multiphysics.

26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin