Run Monte-Carlo Simulation for TL (localized transitions)

Runs a Monte-Carlo (MC) simulation of thermoluminescence (TL) using the generalized one trap (GOT) model. Localized transitions refer to transitions which do not involve the conduction or valence band. These transitions take place between the ground state and an excited state of the trapped charge, and also involve an energy state of the recombination centre. The heating rate in this function is assumed to be 1 K/s.

run_MC_TL_LOC(
  s,
  E,
  times,
  b = 1,
  clusters = 10,
  n_filled = 100,
  r,
  method = "par",
  output = "signal",
  ...
)

Arguments

s

numeric (required): The frequency factor of the trap (s^-1)

E

numeric (required): Thermal activation energy of the trap (eV)

times

numeric (required): The sequence of temperature steps within the simulation (s). The default heating rate is set to 1 K/s. The final temperature is max(times) * b

b

numeric (with default): the heating rate in K/s

clusters

numeric (with default): The number of created clusters for the MC runs. The input can be the output of create_ClusterSystem. In that case n_filled indicate absolute numbers of a system.

n_filled

integer (with default): The number of filled electron traps at the beginning of the simulation (dimensionless). Can be a vector of length(clusters), shorter values are recycled.

r

numeric (required): The localized retrapping ratio (dimensionless)

method

character (with default): Sequential 'seq' or parallel 'par'processing. In the parallel mode the function tries to run the simulation on multiple CPU cores (if available) with a positive effect on the computation time.

output

character (with default): output is either the 'signal' (the default) or 'remaining_e' (the remaining charges/electrons in the trap)

...

further arguments, such as cores to control the number of used CPU cores or verbose to silence the terminal

Value

This function returns an object of class RLumCarlo_Model_Output which is a list consisting of an array with dimension length(times) x clusters and a numeric time vector.

Details

The model

$$ I_{LOC}(t) = -dn/dt = (s * exp(-E/(k_{B} * T))) * (n^2 / (r + n)) $$

Where in the function:
E := the thermal activation energy (eV)
s := the frequency factor for the trap (s^-1)
t := time (s)
\(k_{B}\) := Boltzmann constant (8.617 x 10^-5 eV K^-1)
T := temperature (°C)
n := the instantaneous number of electrons
r := the retrapping ratio for localized transitions

Function version

0.1.0

How to cite

Kreutzer, S., 2022. run_MC_TL_LOC(): Run Monte-Carlo Simulation for TL (localized transitions). Function version 0.1.0. In: Friedrich, J., Kreutzer, S., Pagonis, V., Schmidt, C., 2022. RLumCarlo: Monte-Carlo Methods for Simulating Luminescence Phenomena. R package version 0.1.9. https://CRAN.R-project.org/package=RLumCarlo

References

Pagonis, V., Friedrich, J., Discher, M., Müller-Kirschbaum, A., Schlosser, V., Kreutzer, S., Chen, R. and Schmidt, C., 2019. Excited state luminescence signals from a random distribution of defects: A new Monte Carlo simulation approach for feldspar. Journal of Luminescence 207, 266–272. doi:10.1016/j.jlumin.2018.11.024

Author

Sebastian Kreutzer, Institute of Geography, Heidelberg University (Germany)

Examples

## the short example
run_MC_TL_LOC(
 s = 1e14,
 E = 0.9,
 times = 50:100,
 b = 1,
 method = "seq",
 clusters = 30,
 r = 1) %>%
plot_RLumCarlo()


if (FALSE) {
## the long (meaningful) example
results <- run_MC_TL_LOC(
 s = 1e14,
 E = 0.9,
 times = 50:100,
 method = "par",
 clusters = 100,
 r = 1)

## plot
plot_RLumCarlo(results)

}