5.3 KiB
Usage
Pojectile
Projectile is defined by pycatima.Projectile class. It is initialized using:
Projectile(A, Z, Q=Z, T=0)
where A is mass in u units, Z is proton number, Q is charge state and T is energy in Mev/u units.
import pycatima
p = pycatima.Projectile(238.00032 ,92) # 238U92+ at 0 Mev/u
p = pycatima.Projectile(238.00702 ,92,90,1000) # 238U90+ at 1000 Mev/u
# following methods are defined:
mass = p.A() # get mass of the nucleus us u units
z = p.Z() # get proton number
q = p.Q() # get charge state
energy = p.T() # get energy
p.T(1000) # set energy
Material
Material is defined by pycatima.Material class. The recommended way of initialization is usign the following init signature:
Material(elements, density, thickness, i_potential, mass)
- elements - list of elements, where element is defined as list of [A, Z, STN] A is atomic mass of the element, if 0 natural abundance atomic mass is taken, Z is the proton number of the element, STN is the stoichiometric if >=1.0 or weight fraction if < 1.0
- density - optional, defaults to 0
- thickness - optional, if not defined 0
- i_potential - optional, if <=0 it will be calulated using Bragg rule from elemental ionization potentials
- mass - optional, if <=0 it will be calculated from elements masses and STN number.
Material class has following methods:
- add_element(a, z, stn) - adds another element to the material, see initialization comments for details about, a,z, stn
- ncomponents() - returns number of elements in the material
- density() - returns density
- density(value) - set density
- thickness() - get thickness in g/cm^2
- thickness(value) - set thickness in g/cm^2
- thickness_cm(value) - set thickness in cm
- I() - get mean ionization potential
- I(value) - set mean ionization potential
Default Materials
The material with predefined density and atomic weights can be obtained for elemental targets and some compounds using:
pycatima.get_material(id)
id is integer which identifies material, For elements use 1-99 for elemental targets and >200 for compounds. See available pre-defined compounds in predefined material section in manual./
Example
import pycatima
#H2O with natural atomic masses and Ipot=78eV
h2o = pycatima.Material([[0,1,2],[0,8,1]],density=1.0, i_potential=78)
h2o.thickness_cm(1.0) # 1cm of water
# C target
c_mat = pycatima.get_material(6)
c_mat.thickness(0.1) # set to 0.1g/cm2
Layers
Layers are sequential layers of Material which Projectile passes. The pycatima.Layers class is defined using following signature: Layers() This creates empty layers which needs to be filled by Material class.
Layers clas has following methods:
- add(material) - add material to the layers, material must be Material class
- add_layers(other) - add all material from Layers class other
- num() - returns number of layers
- get_item(i) returns i-th Material class
- __get(i) returns i-th Material class
Example
import pycatima
layers = pycatima.Layers()
# define some materials
graphite = pycatima.get_material(6)
graphite.thickness(0.2)
p10 = pycatima.get_material(pycatima.material.P10)
p10.thickness_cm(2.0)
air = pycatima.get_material(pycatima.material.Air)
air.thickness_cm(2.0)
# now add materials to layers
layers.add(graphite)
layers.add(air)
graphite.thickness(0.1) # change thickness for next layer
layers.add(graphite)
layers.add(p10)
Calculation
Calculations are done using mainly via functions:
- calculate(Projectile, Material)
- calculate_layers(Projectile, Layers)
The calculate function returns Result class and calculate_layers returns MultiResult_class
Example
import pycatima
water = catima.get_material(catima.material.Water)
water.thickness(1.0)
p = catima.Projectile(1,1)
p.T(1000) # set projectile energy to 1000MeV/u
res = catima.calculate(p,water) # now res contains results
d = res.get_dict() # get results as dictionary
p = catima.Projectile(12,6)
water = catima.get_material(catima.material.Water)
water.thickness(10.0)
graphite = catima.get_material(6)
graphite.thickness(1.0)
graphite.density(2.0)
mat = catima.Layers()
mat.add(water)
mat.add(graphite)
# now calculate results for projectile at 1000MeV/u
res = catima.calculate_layers(p(1000),mat)
Results
Results class stores results for 1 layer of Material. It has following variables:
- Ein - Energy at entrance of the material in MeV/u
- Eloss - Energy loss in material in MeV
- Eout - Energy at the end of material in MeV/i
- dEdxi - Stopping power at entrance
- dEdxo - Stopping power at exit
- range - range in the material in g/cm^2
- sigma_E - Energy straggling in MeV/u
- sigma_a - Angular straggling in MeV/u
- sigma_r - range straggling in g/cm^2
- sigma_x - position straggling in cm
- sp - non-reaction probability
- tof - time of flight through the material
MultiResults class stores the results for multiple layers. It consists of following variables:
- total_result - Result class with total results for projectile passing all layers.
- results - list of Result classes, one for each layer in Layers
Config
TODO