Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Massively Parallel Computing of Turbulent Transport in Tokamaks   With the advent of the gyrokinetic formalism, recent developments in
low-noise nonlinear $\delta f$ methods, and enormous gains in computing power,
large-scale gyrokinetic simulations have become an important tool for improved
understanding of anomalous transport in tokamaks. Simulating the non-linear
behaviour requires solving for the perturbations of distrbution function in
five dimensions. We use a particle-in-cell approach to solve the equations via
the non-linear characteristic method. The code has been parallelized for a
variety of architecures (C90, CM-5, T3D) using a 1-D domain decomposition along
the torroidal axis, for which the number of particles in each cell remains
approximately constant. The quasi uniform distribution of particles, which
minimizes load imbalance, coupled with the relatively small movement of
particles across cells, which minimizes communications, makes this problem
ideally suited to massively parallel architectures. We present the performance
of the program as a function of number of processors and problem size, which
demonstrates the near perfect scalability of the code. In addition, we discuss
the scientific results obtained from the code and the types of problems that
will be addressable as the next generation of super-computers become available.

35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph