Accessing Individual Values

To evaluate kinematic quantities at a specific beam energy and kinematic variable value, use kinematics_at_beam_energy_and_variable().

This method automatically handles multi-valued solutions and always returns lists.

Syntax

from reaction_kinematics import Reaction

rxn = Reaction("p", "3H", "n", "3He")
# Proton + Tritium Reaction

r = rxn.kinematics_at_beam_energy_and_variable(1.2, "theta3", 2.13)
# 2.13 is in radians
print(r)

This will return:

{'coscm': [-0.9813047694699246], 
'theta_cm': [2.9479854759117416], 
'theta3': [2.13], 
'theta4': [0.054070851022814864], 
'e3': [0.005237930117122223], 
'e4': [0.43100601988343396], 
'v3': [0.003338681989975168], 
'v4': [0.017517730726598162], 
'p3': [3.136927647029636], 
'p4': [49.204196838704895]}

Parameters:

  • beam_energy : Beam kinetic energy in MeV
  • var_name : Independent variable (e.g. "theta3", "theta4", "theta_cm", "coscm")
  • var_value : Value at which to evaluate (radians for angles)
  • return_variables : Dependent variables to return — string, list, or None for all