/DFS/LASER

Block Format Keyword Enable to model laser impact taking into account laser-matter interaction. 1

Format

Field	Contents	SI Unit Example
`laser_ID`	Laser line identifier. (Integer, maximum 10 digits)
`unit_ID`	Unit Identifier (Integer, maximum 10 digits)
`S`_LAS	Laser intensity scale factor. (Real)
`fct_ID`_LAS	Laser intensity time function number. (Real)
`S`_TAR	Target absorption scale factor. (Real)
`fct_ID`_TAR	Target absorption temperature function number. (Integer)	$[K]$
`H`_n	Plasma parameter. $H_{n} = \frac{h \cdot v}{k_{B}}$ Where, `h` Planck constant. `k`_B Boltzmann constant. `v` Laser frequency. (Real)	$[K]$
`VC`_p	Enthalpy of vaporization. (Real)	$[\frac{J}{kg \cdot K}]$
`K`₀	Inverse bremsstrahlung coefficient `K`₀. 6 (Real)	$[m^{5}]$
`R`_d	Inverse bremsstrahlung coefficient $\frac{R_{d}}{k_{B}}$ . 6 (Real)	$[K]$
`K`_S	Compliment absorption in vapor. 5 (Real)	$[\frac{m^{5}}{{mole}^{2}}]$
`N`_p	Number of plasma elements between laser and target. (Integer)
`N`_c	Target element number. 1 (Integer)
`IEL`_i	List of plasma elements (i=1,..., `N`_p). 3 (Integer)

Laser-matter interaction requires material laws enabling different phases: solid, liquid, and gas. It also needs to have a correct behavior with high pressure (several megabars) and high temperatures (more than 10000K). /MAT/LAW26 (SESAM) must also be used.
This option is available only in 2D analysis.
Plasma elements must be entered in the order from laser to target.
It is assumed the laser beam is perpendicular to the target.
$K_{S} = 67000 {(\frac{ρ}{w_{A}})}^{2}$ is taken from K. Daree's plasma ignition model.
(1)
$I = I_{0} - \sum_{n_{l a s e r}}^{n_{t a r g e t}} I_{a b s o r b e d}$
(2)
$I_{a b s o r b e d} = (1 - e^{- K Δ x}) I$
(3)
$K = \frac{4}{3} \sqrt{\frac{2 π}{3 k_{B} T}} \frac{n_{e} n_{i} Z^{2} e_{6}}{h c m_{e}^{\frac{3}{2}} v^{3}} (1 - e^{- \frac{h v}{k_{B} T}}) g f f = K_{0} {(\frac{R_{d}}{h v})}^{3} {(\frac{R_{d}}{k_{B} T})}^{\frac{1}{2}} (n_{i}^{2} Z^{3}) (1 - e^{- \frac{h v}{k_{B} T}}) g f f$

Usually, $K_{0} = 9.468 \times 10^{- 4} m^{5}$ and $\frac{R_{d}}{k} = 157750 K$ .