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Subsections


7.1.14 Dust: dustscheme=dust_k3mon_03

In this section the parameters for dustscheme=dust_k3mon_03 (simple 2-bin dust scheme for forsterite dust) are described:

7.1.14.1 integer n_dustgrainradius

The number of dust grain radius bins (including one for the monomers) is specified with
integer n_dustgrainradius f=I8 b=4 n='Number of dust grain radius bins' &
  c1='Includes: bin for monomers'
2
The default value is 1 (to avoid an empty array). The value should be the same as the upper dimension in real ar_dustgrainradius. For the current dust scheme, there should always be exactly two bins.

7.1.14.2 real ar_dustgrainradius

The radii of the dust grains are specified with e.g.
real ar_dustgrainradius f=E10.4 b=4 p=1 d=(1:2) n='Dust grain radii' u=cm
0.0
1.0E-04
The default value is 0.0.

7.1.14.3 real c_dust01

The density of the grain material is specified with e.g.
real c_dust01 f=E15.8 b=4 n='Density of grain material' u=g/cm^3
3.3E+00

7.1.14.4 real c_dust02

The atomic weight of the "dust monomer" is specified with e.g.
real c_dust02 f=E15.8 b=4 n='Atomic weight of dust monomer' u=u
140.71
The value 140.71 should be appropriate for forsterite (Mg$_2$SiO$_4$). The unit is the atomic mass unit. The default value is 0.0.

7.1.14.5 real c_dust03

The number fraction of the rarest component is specified with e.g.
real c_dust03 f=E15.8 b=4 n='Number fraction of rarest component' u=1 &
  c0='For Mg2SiO4, Mg is the rarest, its fraction is 3.1187E-05' &
  c1='Mg2SiO4 contains 2 Mg -> * 1/2 -> 1.55935e-05'
1.55935e-05
For Mg$_2$SiO$_4$ the rarest component is (usually) Mg$_2$. So, half the magnesium abundance is required as value. The default value is 0.0.

7.1.14.6 real c_dust04

The lower dust limit fraction is specified with e.g.
real c_dust04 f=E15.8 b=4 n='Lower dust limit fraction' u=1
1.0E-10
It is used in the calculation of the settling velocity where a division by the total density of monomers and dust is required. To prevent this denominator to become zero a term $c_{\rm dust04} \rho$ is added. The default value is 0.0.

7.1.14.7 real c_dust05

The minimum number of monomers during condensation is specified with e.g.
real c_dust05 f=E15.8 b=4 n='Minimum number of monomers during condensation' u=1
10.0
For very small grains (just one or very few monomers) the condensation rates can be very small in this dust model: nucleation that would form already small clumps of monomers is not considered. Therefore, to speed things up a minimum number of monomers can be given that is considered for the condensation rate. With 1.0 or smaller values the enhancement is switched off. The default value is 0.0.

7.1.14.8 real c_dust06

The sticking coefficient for the condensation rate is specified with e.g.
real c_dust06 f=E15.8 b=4 n='Sticking coefficient' u=1 &
  c0='For C-rich dust: 0.37; can be between 0 and 1'
1.0
The default value is 0.0.


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