radsafer (version 2.4.0)

dk_correct: Correct activity-dependent value based on radioactive decay.

Description

Decay-corrected values are provided. Either a single or multiple values are computed. The computation is made either based on a single radionuclide, or based on user-provided half-life, with time unit. The differential time is either computed based on dates entered or time lapsed based on the time unit. Time units must be consistent. Decay-correct a source to today's date by assigning a reference date1 and allowing default date2, the system date.

Usage

dk_correct(
  RN_select = NULL,
  half_life = NULL,
  time_unit = NULL,
  time_lapse = NULL,
  date1 = NULL,
  date2 = Sys.Date(),
  A1 = 1,
  num = FALSE
)

Value

Decay adjusted activity or related parameter. See A1.

Arguments

RN_select

identify the radionuclide of interest in the format, "Es-254m" Required unless half_life is entered.

half_life

Required if RN_select is not provided.

time_unit,

acceptable values are "years", "days", "hours", "minutes", and "seconds". May be shortened to "y", "d", "h", "m", and "s". Required if half_life or time_lapse are to be entered.

time_lapse

a single value or vector of values representing time lapsed since date1, with units identified in time_unit. Positive values represent time past date1. Negative values represent time before date1. Required unless date1 is entered.

date1

Reference date - Required unless using time_lapse. Format is required to be date-only: "YYYY-MM-DD" (e.g. "1999-12-31"). If half_life is short relative to calendar dates, use time_lapse instead.

date2

Date or dates of interest. Default is today's date, obtained from the computer operating system.

A1

The reference activity or related parameter, such as count rate or dose rate. Default value is 1, resulting in a returned value that may be used as a correction factor.

num

Set for TRUE to facilitate as.numeric results. Default = FALSE.

See Also

Other decay corrections: dk_pct_to_num_half_life(), dk_time()

Examples

# RN_select and date1 (saving numerical data)
my_dks <- dk_correct(
  RN_select = "Sr-90",
  date1 = "2009-01-01",
  date2 = "2019-01-01",
  num = TRUE
)

#   RN_select and time_lapse (random sample)
dk_correct(
  RN_select = base::sample(RadData::ICRP_07.NDX$RN, 1),
  time_lapse = 1:10,
  time_unit = base::sample(c("y", "d", "h", "m", "s"), 1)
)

#   half_life and date1
dk_correct(
  half_life = 10,
  time_unit = "y",
  date1 = "2009-01-01",
  date2 = c(
    "2015-01-01",
    "2016-01-01",
    "2017-01-01"
  )
)

#   half_life and time_lapse
dk_correct(
  half_life = 10,
  time_lapse = 10,
  time_unit = "y"
)

# decay to today
dk_correct(RN_select = "Sr-90", date1 = "2009-01-01")

# reverse decay - find out what readings should have been in the past given today's reading of 3000
dk_correct(
  RN_select = "Sr-90",
  date1 = "2019-01-01",
  date2 = c("2009-01-01", "1999-01-01"),
  A1 = 3000
)