---
title: PROFILES.TXT
section: 5
---

# NAME
profiles.txt --- Kinetic plasma profiles data for **gray**(1)

# FORMAT
The plasma profiles can be specified in two ways: either as the free parameters
of a simple analytical model, or as numerical data in a tabular format.

## analytical profiles
The format for the analytical profiles is as follows:

    n₀ a b     ! comment
    T₀ T₁ c d
    Z_eff

The first line contains the parameters for the electron density as a function
of the normalised poloidal flux *n(ψ)*, which in units of 10¹⁹ m⁻³ is given as:

    n(ψ) = n₀(1 - ψ^a)^b

Similarly, the second line contains the parameters for the electron temperature
*T(ψ)*, which is defined in units of keV as:

    T(ψ) = (T₀ - T₁)(1 - ψ^c)^d + T₁

The last lines contains the (constant) value of the effective charge.

## numerical profiles
The format for the numerical consists of a table with the following columns:
*radial coordinate*, *temperature*, *density*, *effective charge*.
The first line is a header specifying the number of table rows and subsequent
lines contains the whitespace-separated records, one row per line:

    nrows  ! comment
    ρ₁ T₁ n₁ Z₁
    ρ₂ T₂ n₂ Z₂
    ...


# EXAMPLES
1. A valid analytical profiles.txt file

        10 0.3 3  ! n₀, a, b
        14 0 2 8  ! T₀, T₁, c, d
        1.0       ! Z_eff

2. A valid numerical profiles.txt file

        100  ! ρ_t T_e n_e Z_eff
        0.005025  17.9399  24.1717  1.64001
        0.095477  17.4336  23.7527  1.56178
        0.175879  16.9632  23.2699  1.65915
        0.246231  13.7457  22.9230  1.72905
        0.306533  10.4874  22.6312  1.76446
        0.457286  6.59895  21.7133  1.74971
        0.577889  4.74975  19.5653  1.60959

# SEE ALSO
**gray**(1)