baroncs 0.1.5

Finds the charge state distribution of a given element.

Table of Contents

• Table of Contents
• baroncs
• Installation
• Usage
  • Charge state distribution
  • Dataframe
  • Mean charge state and standard deviation
• Sources

baroncs

This package is based on Baron's corrected formula [^1]. It calculates the charge state distribution of ions in a gas target.

Installation

To install the package, run the following command in the terminal:

pip install baroncs

For developer installation, run the following command in the terminal:

git clone https://github.com/jako4295/baroncs.git
pip install -e baroncs

Usage

Charge state distribution

By default the charge state distribution is using e0=931.5 and energy=4.2 to calculate the relativistic beta factor. However, these energies can also be specified. The beta factor can also be specified directly. These examples are shown below:

To obtain the charge state distribution for a given atom and energy, run the following python code:

import baroncs as bcs

charge_obj = bcs.ChargeState()
distx, disty = charge_obj.charge_state_distribution(
    atomic_nr=82,  # atomic number of the projectile
    energy=4.2,  # energy of the projectile in MeV/u
    e0=931.5,  # rest energy in MeV
    dist_onesided_len=5,  # length of the on each side of the mean charge state
    plot=True,  # plot the distribution
)

This returns the following plot:

To calculate the charge state distribution given a beta factor, run the following python code:

import baroncs as bcs

charge_obj = bcs.ChargeState()
distx, disty = charge_obj.charge_state_distribution(
    atomic_nr=82,  # atomic number of the projectile
    beta=0.09,  # beta factor
    dist_onesided_len=5,  # length of the on each side of the mean charge state
    plot=True,  # plot the distribution
)

This returns the following plot:

If the dist dist_onesided_len is changed then we get the following:

distx, disty = charge_obj.charge_state_distribution(
    atomic_nr=82,  # atomic number of the projectile
    energy=4.2,  # energy of the projectile in MeV/u
    e0=931.5,  # rest energy in MeV
    dist_onesided_len=10,  # length of the on each side of the mean charge state
    plot=True,  # plot the distribution
)

If it is desired to create the plot in a different way then distx and disty corresponds to the x and y values of the plt.bar function.

Dataframe

To create a dataframe with information about each atomic number, run the following python code:

import baroncs as bcs

charge_obj = bcs.ChargeState()
df = charge_obj.dataframe()  # this uses default e0=931.5, energy=4.2

The dataframe has the following columns:

• Name: atomic number of the projectile (this is the index of the dataframe)
• Atomic Number: atomic number of the projectile
• Commonest Isotope: the most common isotope of the projectile
• Abundance (%): the abundance of the most common isotope
• Melting Point: the melting point of the projectile
• Nearest Q (A/Q=8): the nearest charge state to A/Q=8
• Actual Q/A: the actual charge state of the projectile
• A/Q: the A/Q of the projectile
• Mean Charge: the mean charge state of the projectile
• Most Probable: the most probable charge state of the projectile
• Standard Deviation: the standard deviation of the charge state distribution
• Probable %: the probability of the most probable charge state
• Magnetic Rigidity: the magnetic rigidity of the projectile

If it is not desired to get all atoms, then we can specify which atoms to get by using the atoms argument:

import baroncs as bcs

charge_obj = bcs.ChargeState()
df = charge_obj.dataframe(atoms=[54, 82])  # this uses default e0=931.5, energy=4.2

This will only return the dataframe for Xenon and Lead (atomic number 54 and 82 respectively).

Mean charge state and standard deviation

Both the mean charge state and the standard deviation uses the relativistic beta factor. If charge_obj.charge_state_distribution is called then the relativistic beta function is calculated and stored in charge_obj.beta (this is the one that will be used if charge_obj.mean_charge_state or charge_obj.std_charge_state is called).

If it is desired to calculate the mean charge state and standard deviation with a different beta factor, then it can be specified either using e0 and energy, or specifying the beta factor directly. These examples are shown below: Using e0 and energy

import baroncs as bcs

charge_obj = bcs.ChargeState()
charge_obj.beta = (4.2, 931.5)  # set the beta factor (energy, e0)
mean_charge_state = charge_obj.mean_charge_state(
    atomic_nr=82,  # atomic number of the projectile
)
std_charge_state = charge_obj.std_charge_state(
    atomic_nr=82,  # atomic number of the projectile
)

Specifying beta directly

import baroncs as bcs

charge_obj = bcs.ChargeState()
charge_obj.beta = 0.09  # set the beta factor directly
mean_charge_state = charge_obj.mean_charge_state(
    atomic_nr=82,  # atomic number of the projectile
)
std_charge_state = charge_obj.std_charge_state(
    atomic_nr=82,  # atomic number of the projectile
)

Sources

[^1]: Charge exchange of very heavy ions in carbon foils and in the residual gas of GANIL cyclotrons