pwiDB

Fit Function: `SPTAEX`

Fit Function	$Y (E_{0}, α) = Y (E_{0}, 0) {\cos [{(\frac{α}{α_{0}} \frac{π}{2})}^{c}]}^{- f} \exp {b (1 - \frac{1}{\cos [{(\frac{α}{α_{0}} \frac{π}{2})}^{c}]})}$
Comments	Extended Yamamura formula

Python

Arguments

name	description	units	type(s)
`alpha`	projectile impact angle measure from normal to the surface	deg	`float`, `np.ndarray`
`f`	fit coefficient		`float`
`b`	fit coefficient		`float`
`c`	fit coefficient		`float`
`Y0`	fit coefficient: Y(E0, 0), the sputtering yield at E0, normal incidence		`float`
`alpha0`	fit coefficient	rad	`float`

Return values

name	description	units	type(s)
`Y(E0, alpha)`	sputtering yield		`float`, `np.ndarray`

Code

def sptaex(alpha, f, b, c, Y0, alpha0):
    alpha = np.radians(alpha)
    aratio = alpha * pio2 / alpha0
    cs = np.cos(aratio ** c)
    xs1 = np.exp(b * (1 - 1 / cs))
    xs2 = 1 / cs**f
    Y = Y0 * xs1 * xs2
    return np.clip(Y, 0, None)

Fit Function: SPTAEX

Python

Fit Function: `SPTAEX`