pcdsdevices.ccm.theta_to_alio

pcdsdevices.ccm.theta_to_alio(theta: float, theta0: float, gr: float, gd: float) → float

Converts theta angle (rad) to alio position (mm).

Theta_B: scattering angle, the angle reduces when rotating clockwise

(Bragg angle)

Theta_0: scattering angle offset of the Si (111) first crystal Delta_Theta: the effective scattering angle (adjusted with Alio stage) R = 0.003175m: radius of the sapphire ball connected to the Alio stage D = 0.232156m: distance between the Theta_B rotation axis and the center

of the sapphire sphere located on the Alio stage. note: The current value that we’re using for D is 0.231303 - possibly measured by metrology

Theta_B = Theta_0 + Delta_Theta Conversion formula: x = f(Delta_Theta) = D * tan(Delta_Theta)+(R/cos(Delta_Theda))-R Note that for ∆θ = 0, x = R