Be exposure age calculator MATLAB function reference Version 2

2.4 desilets2006sp.m
Syntax:
scalingfactor = desilets2006sp(h,Rc)
Calculates the geographic scaling factor for cosmogenic-nuclide production for particular cutoff rigidity and atmospheric
pressure according to the scheme in:
Desilets D., Zreda M., Prabu T., 2006. Extended scaling factors for in situ cosmogenic nuclides: New measurements
at low latitude. Earth and Planetary Science Letters, v. 246, pp. 265-276.
The input arguments are h, atmospheric pressure (hPa), and Rc, cutoff rigidity (GV). Accepts vector arguments.
This function:
Converts atmospheric pressure h (hPa) to atmospheric depth x (g · cm −2 ) by x = 1.0197h.
Assigns cutoff rigidities below 2 GV a value of 2 GV.
Obtains the effective attenuation length in air Λ eff,sp via Equation (4) in the source paper:
Λ eff,sp =
1033 − x
g(1033, R C ) − g(x, R C )
(27)
where R C is the cutoff rigidity (GV) and the function g(x, R C ) is:
g(x, R C ) =
+ 1 2
+ 1 3
+ 1 5
n [ 1 + exp ( −αR −k )] −1
C x (28)
[ ]
a0 + a 1 R C + a 2 RC
2 x
2
(29)
[ ]
a3 + a 4 R C + a 5 RC
2 x
3
(30)
[ ]
a6 + a 7 R C + a 8 RC
2 x
4
(31)
given constants:
n
α
k
a 0
a 1
a 2
a 3
a 4
a 5
a 6
a 7
a 8
1.0177 × 10 −2
1.0207 × 10 −1
−3.9527 × 10 −1
8.5236 × 10 −6
−6.3670 × 10 −7
−7.0814 × 10 −9
−9.9182 × 10 −9
9.9250 × 10 −10
2.4925 × 10 −11
3.8615 × 10 −12
−4.8194 × 10 −13
−1.5371 × 10 −14
26