sub_G01_electron.f90

中文 English

直接用途

sub_G01_electron 执行电子碰撞后的速度/粒子状态更新，包括激发和电离相关分支。

参数表

参数	方向	shape/范围	含义与局部约定
v	in/out	(1:3)	入射粒子速度向量。
me	in	scalar or caller-provided array	电子质量。
mn	in	scalar or caller-provided array	中性粒子质量。
e	in	scalar or caller-provided array	基本电荷或电荷单位换算因子。
energy_excitation	in	scalar or caller-provided array	激发能量阈值。
energy_ionization	in	scalar or caller-provided array	电离能量阈值。
x	in	(1:3)	粒子位置或 HYPRE solution 句柄，具体取决于接口上下文。
par_e	out	(1:6)	电子粒子数组。
par_i	out	(1:6)	离子粒子数组。
vti	in	scalar or caller-provided array	中性粒子热速度。
vd	in	(1:3)	漂移速度向量。
eV	in	scalar or caller-provided array	电子伏特换算因子。

局部假设

碰撞例程假定粒子数组 par(1:6,...) 中 1:3 是位置、4:6 是速度。随机数来自 Fortran random_number；能量、截面、密度和时间步单位必须由调用方保持自洽。这里不替调用方设置随机种子。

实现逻辑

实现先计算或复用 nu_max，再用 null-collision 概率抽取候选粒子；每个候选粒子按截面权重选择碰撞类型并更新速度或粒子数组。

调用注意

本页只说明该例程本身的调用边界和实现事实；完整接口声明和源码级 API 仍以英文侧的 generated API 为准。

Direct Purpose

sub_G01_electron electron collision and post-collision velocity update.

Parameter Table

Parameter	Direction	Shape/range	Meaning and local convention
v	in/out	(1:3)	real (1:3), electron velocity.
me	in	scalar or caller-provided array	real, electron mass.
mn	in	scalar or caller-provided array	real, neutral particle mass.
e	in	scalar or caller-provided array	real, unit charge.
energy_excitation	in	scalar or caller-provided array	real, excitation energy, if > 0 then excitation is applied.
energy_ionization	in	scalar or caller-provided array	real, ionization energy, if > 0 then ionization is applied.
x	in	(1:3)	real (1:3), electron position.
par_e	out	(1:6)	real (1:6), new electron particle array.
par_i	out	(1:6)	real (1:6), new ion particle array.
vti	in	scalar or caller-provided array	real, thermal velocity of ion.
vd	in	(1:3)	real (1:3), drifting velocity of ion.
eV	in	scalar or caller-provided array	real, electron volt conversion factor.

Local Assumptions

Collision routines assume par(1:6,...) stores position in 1:3 and velocity in 4:6. Random numbers come from Fortran random_number. Units of energy, cross section, density, and time step must be kept self-consistent by the caller. These routines do not seed the RNG.

Implementation Notes

The implementation computes or reuses nu_max, samples candidate particles with a null-collision probability, then selects collision type by cross-section weights and updates velocity or particle arrays.

Generated API

Electron collision and post-collision velocity update.

Functions

subroutine sub_g01_electron(v, me, mn, e, energy_excitation, energy_ionization, x, par_e, par_i, vti, vd, ev)

This subroutine handles electron-neutral collisions, including elastic scattering, excitation, and ionization processes. The post-collision electron velocity is updated according to the selected collision type. For ionization events, a secondary electron and an ion are generated, with their velocities sampled from the corresponding distributions.

Author

Lihuan XIE (2025/12/18)

Parameters:

• v – [inout] real (1:3), electron velocity.

• me – [in] real, electron mass.

• mn – [in] real, neutral particle mass.

• e – [in] real, unit charge.

• energy_excitation – [in] real, excitation energy, if > 0 then excitation is applied.

• energy_ionization – [in] real, ionization energy, if > 0 then ionization is applied.

• x – [in] real (1:3), electron position.

• par_e – [out] real (1:6), new electron particle array.

• par_i – [out] real (1:6), new ion particle array.

• vti – [in] real, thermal velocity of ion.

• vd – [in] real (1:3), drifting velocity of ion.

• eV – [in] real, electron volt conversion factor.