The relationship of each units The conversion between the pascal and the torr is via the standard atmosphere which is defined as exactly equal to both 760 Torr and 1.01325X 105 Pa, given by 760 p'(Torr P 1.0133×10 The pressure can be related to the number density in particles per cubic meter by the perfect gas laW, p=nkT Where k is boltzmann's constant
The relationship of each units n The conversion between the Pascal and the Torr is via the standard atmosphere which is defined as exactly equal to both 760 Torr and 1.01325× 105 Pa, given by n The pressure can be related to the number density in particles per cubic meter by the perfect gas law, where k is Boltzmann’s constant. ( ) 1 . 0133 10 760 ' ( ) 5 p Torr p Pa p nkT
The conversion factor between the neutral number density and the background pressure 1.0133×10 particles/ 760MD(70m)=320×102P)(7om) a Here the temperature is evaluated as 300K
The conversion factor between the neutral number density and the background pressure: n Here, the temperature is evaluated as 300K. '( ) 3.220 10 '( ) 760 1.0133 10 ( / ) 22 5 3 p Torr p Torr kT n particles m
2.2 Particle distribution functions If the particles are allowed to interact and equilibrate their velocities and energies become distributed over a range of values described by the Maxswell-Boltzmann distribution function 2. 2. 1 Velocity distribution functions velocity distribution function means the proportion of the number of particles in a unit velocity space volume to the total particles if we define dnx: the number of particles in the velocity interval between v and v +dy 12 ny f(v)= 22 2kT expl-aix 2KT
2.2 Particle distribution functions If the particles are allowed to interact and equilibrate, their velocities and energies become distributed over a range of values described by the Maxswell-Boltzmann distribution function. 2.2.1 Velocity distribution functions velocity distribution function means the proportion of the number of particles in a unit velocity space volume to the total particles. if we define dnx : the number of particles in the velocity interval between vx and vx+dvx ] 2 ) exp[ 2 ( ) ( 2 2 1 2 1 kT mv kT n m dv dn f v x x x x
The number of particles in a unit cubical volume in velocity space d、3N27)2eXm Xv 2kT 1+1+1 dn 4n m f(v) 3/2 12 2kT v expl 2kT
n The number of particles in a unit cubical volume in velocity space: ) exp 2 ( 2 3 2 3 3 kT n m dv dv dv d n x y z xyz ] 2 [ 2 kT mv 2 2 2 2 x y z v v v v ] 2 ) exp[ 2 ( 4 ( ) 2 3 / 2 2 2 1 kT mv v kT n m dv dn f v v
The figure shows schematically the distribution of speed f(v)as a function of the speed v for three kinetic temperatures, T1<T2<T3 TI dv T2 T3 Total velocity
The figure shows schematically the distribution of speed f(v) as a function of the speed v for three kinetic temperatures, T1<T2<T3