Fe55#

class msfc_ccd.Fe55(probability_k_alpha_1=0.162, probability_k_alpha_2=0.082, probability_k_beta=0.0338, energy_k_alpha_1=<Quantity 5.89875 keV>, energy_k_alpha_2=<Quantity 5.88765 keV>, energy_k_beta=<Quantity 6.49045 keV>, temperature=<Quantity -55. deg_C>)[source]#

Bases: object

The X-rays emitted by an \(^{55}\text{Fe}\) source.

An \(^{55}\text{Fe}\) nucleus captures one of its own electrons and becomes \(^{55}\text{Mn}\), which emits an X-ray at one of two energies as the resulting hole is filled. Both energies are known to much better than the resolution of these sensors, so the charge that an X-ray releases is a ruler which can be used to measure the gain.

How much charge that is depends on the temperature of the sensor, through the energy needed to create one electron-hole pair, so temperature has to be set to the temperature the sensor was at.

Examples

The number of electrons released by each line.

import msfc_ccd

fe55 = msfc_ccd.Fe55()

print(f"K-alpha: {fe55.energy_k_alpha:0.4f} -> {fe55.charge_k_alpha:0.1f}")
print(f"K-beta:  {fe55.energy_k_beta:0.4f} -> {fe55.charge_k_beta:0.1f}")

K-alpha: 5.8950 keV -> 1602.3 electron
K-beta:  6.4905 keV -> 1764.2 electron

Warming the sensor to room temperature would change the answer by almost a percent.

import astropy.units as u

warm = msfc_ccd.Fe55(temperature=300 * u.K)

print(f"{warm.charge_k_alpha:0.1f} at {warm.temperature}")

1616.9 electron at 300.0 K

Attributes

`charge_k_alpha`	The electrons released in silicon by a K-\(\alpha\) X-ray.
`charge_k_beta`	The electrons released in silicon by a K-\(\beta\) X-ray.
`energy_k_alpha`	The mean energy of the K-\(\alpha\) X-rays.
`energy_k_alpha_1`	The energy of the K-\(\alpha_1\) X-rays.
`energy_k_alpha_2`	The energy of the K-\(\alpha_2\) X-rays.
`energy_k_beta`	The energy of the K-\(\beta\) X-rays.
`probability_k_alpha`	The probability of emitting a K-\(\alpha\) X-ray of either energy.
`probability_k_alpha_1`	The probability of emitting a K-\(\alpha_1\) X-ray.
`probability_k_alpha_2`	The probability of emitting a K-\(\alpha_2\) X-ray.
`probability_k_beta`	The probability of emitting a K-\(\beta\) X-ray.
`temperature`	The temperature of the sensor when the exposure was gathered.

Methods

__init__([probability_k_alpha_1, ...])

Inheritance Diagram

Parameters:

probability_k_alpha_1 (float)
probability_k_alpha_2 (float)
probability_k_beta (float)
energy_k_alpha_1 (Quantity)
energy_k_alpha_2 (Quantity)
energy_k_beta (Quantity)
temperature (Quantity)

property charge_k_alpha: Quantity#: The electrons released in silicon by a K-\(\alpha\) X-ray.

property charge_k_beta: Quantity#: The electrons released in silicon by a K-\(\beta\) X-ray.

property energy_k_alpha: Quantity#: The mean energy of the K-\(\alpha\) X-rays.

energy_k_alpha_1: Quantity = <Quantity 5.89875 keV>#: The energy of the K-\(\alpha_1\) X-rays.

energy_k_alpha_2: Quantity = <Quantity 5.88765 keV>#: The energy of the K-\(\alpha_2\) X-rays.

energy_k_beta: Quantity = <Quantity 6.49045 keV>#: The energy of the K-\(\beta\) X-rays.

property probability_k_alpha: float#

The probability of emitting a K-\(\alpha\) X-ray of either energy.

The two are 11 eV apart, far closer than these sensors can resolve, so they are treated as one line.

probability_k_alpha_1: float = 0.162#

The probability of emitting a K-\(\alpha_1\) X-ray.

This and probability_k_alpha_2 sum to 0.244, against the 0.245 (7) measured by Schötzig [2000].

probability_k_alpha_2: float = 0.082#: The probability of emitting a K-\(\alpha_2\) X-ray.

probability_k_beta: float = 0.0338#

The probability of emitting a K-\(\beta\) X-ray.

The 0.0338 (9) measured by Schötzig [2000], summed over the K-\(\beta_{1,3}\) and K-\(\beta_5\) components, which these sensors cannot resolve from one another.

temperature: Quantity = <Quantity -55. deg_C>#

The temperature of the sensor when the exposure was gathered.

The default is the temperature the ESIS cameras are designed to run at. The energy needed to create one electron-hole pair falls as silicon warms, so a sensor at room temperature would release almost a percent more charge for the same X-ray.