rice (version 1.1.1)

howmanyC14: Amount of C14 particles in a sample

Description

Find the amount of remaining C14 atoms in a sample, given its weight and age.

Usage

howmanyC14(
  age,
  wght = 1,
  use.cc = TRUE,
  Av = 6.02214076e+23,
  C14.ratio = 1.176e-12,
  format = "g",
  cc = 1,
  postbomb = FALSE,
  cc.dir = NULL,
  thiscurve = NULL,
  talk = TRUE,
  decimals = 3
)

Value

The estimated number of C14 atoms.

Arguments

age

The age of the sample (in cal BP per default, or in C14 BP is use.cc=FALSE).

wght

The weight of the sample (in mg). Defaults to 1 mg.

use.cc

Whether or not to use the calibration curve. If set to use.cc=FALSE, then we assume that the age is the radiocarbon age (this enables ages beyond the reach of the calibration curves to be used).

Av

Avogadro's number, used to calculate the number of carbon atoms in the sample.

C14.ratio

The 14C/C ratio at F=1 (AD 1950).

format

The format of the printed numbers. Defaults to either scientific (for large numbers) or as fixed-point, depending on the size of the number.

cc

calibration curve for C14 (see caldist()).

postbomb

Whether or not to use a postbomb curve (see caldist()).

cc.dir

Directory of the calibration curves. Defaults to where the package's files are stored (system.file), but can be set to, e.g., cc.dir="curves".

thiscurve

As an alternative to providing cc and/or postbomb, the data of a specific curve can be provided (3 columns: cal BP, C14 age, error).

talk

Whether or not to provide feedback (defaults to TRUE).

decimals

Number of decimals to be returned for F and atom counts.

Author

Maarten Blaauw

Details

The number of carbon atoms in the sample is estimated. Given the known C14/C ratio at F=1, and given the sample's age, we can estimate the number of remaining C14 atoms.

Examples

  howmanyC14(0) # recent sample
  howmanyC14(55e3) # at dating limit
  howmanyC14(145e3) # way beyond the dating limit, 1 C14 atom per mg remains