R/RN_bin_screen_phot.R

In radsafer: Radiation Safety

#' Search for radioisotopes that dominate a specified energy bin
#'
#' Identify photon emitters that represent a target range of energies, while screening
#' out other selected energy ranges. This may be helpful for identifying radionuclides 
#' in low-definition spectroscopy or in selecting representative spectra for modeling
#' shielding.
#'
#' @family radionuclides
#' @seealso [RN_plot_spectrum()]
#'
#' @param E_min target energy range minimum in MeV, default = 0
#' @param E_max target energy range maximum in MeV, default = 10
#' @param min_prob minimum probability of selected range with default = 0.
#' @param min_half_life_seconds minimum half-life in seconds.
#'  Use multiplier as needed, e.g. 3 * 3600 for 3 hours. Default = NULL,
#' @param max_half_life_seconds maximum half-life. See min_half_life_seconds.
#' @param no_E_min,no_E_min2  minimum energies in ranges to minimize in MeV, default = 0
#' @param no_E_max,no_E_max2  maximum energies in bins to minimize in MeV, default = 10
#' @param no_min_prob,no_min_prob2 minimum probability to minimize with default = 100 (no minimum).
#'
#' @importFrom rlang .data
#'
#' @examples
#' RN_bin_screen_phot(
#'   E_min = 0.1, E_max = 0.3,
#'   min_prob = 0.4, min_half_life_seconds = 30 * 24 * 3600,
#'   max_half_life_seconds = 3.153e7, no_E_min = 0.015,
#'   no_E_max = 0.0999, no_min_prob = 0.05, no_E_min2 = 0.301, no_E_max2 = 10, no_min_prob2 = 0.01
#' )
#' @return radionuclides that match selection criteria
#'
#' @export
RN_bin_screen_phot <- function(E_min = 0,
                            E_max = 10,
                            min_prob = 0,
                            min_half_life_seconds = NULL,
                            max_half_life_seconds = NULL,
                            # screen out
                            no_E_min = 0, no_E_max = 10,
                            no_min_prob = 100,
                            no_E_min2 = 0, no_E_max2 = 10,
                            no_min_prob2 = 100) {
  # screen in - photon in this range
  p <- RadData::ICRP_07.RAD %>%
    dplyr::filter(.data$is_photon == TRUE) %>%
    dplyr::filter(.data$E_MeV > E_min) %>%
    dplyr::filter(.data$E_MeV < E_max) %>%
    dplyr::filter(.data$prob > min_prob)
  # half-life search
  j <- dplyr::left_join(p[, 1:4], RadData::ICRP_07.NDX[, c(1:4, 32)],
                        by = "RN"
  )
  dk_const <- function(half_life_seconds) log(2) / half_life_seconds
  if (!is.null(min_half_life_seconds)) {
    lambda_max <- dk_const(min_half_life_seconds)
    j <- j %>% dplyr::filter(.data$decay_constant < lambda_max)
    j
  }
  if (!is.null(max_half_life_seconds)) {
    lambda_min <- dk_const(max_half_life_seconds)
    j <- j %>% dplyr::filter(.data$decay_constant > lambda_min)
    j
  }
  # screen out #1 - photons in this range
  no_list1 <- RadData::ICRP_07.RAD %>%
    dplyr::filter(.data$RN %in% j$RN) %>%
    dplyr::filter(.data$E_MeV > no_E_min) %>%
    dplyr::filter(.data$E_MeV < no_E_max) %>%
    dplyr::filter(.data$prob > no_min_prob)
  # screen out #2 - photons in this range
  no_list2 <- RadData::ICRP_07.RAD %>%
    dplyr::filter(.data$RN %in% j$RN) %>%
    dplyr::filter(.data$E_MeV > no_E_min2) %>%
    dplyr::filter(.data$E_MeV < no_E_max2) %>%
    dplyr::filter(.data$prob > no_min_prob2)
  # all photons in screened RN
  final <- RadData::ICRP_07.RAD %>%
    dplyr::filter(.data$RN %in% j$RN) %>%
    dplyr::filter(!.data$RN %in% no_list1$RN) %>%
    dplyr::filter(!.data$RN %in% no_list2$RN)
  unique(final$RN)
}