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--- tof_powder_extinction [2016/11/03 20:51] – created pamwhitfield
+++ tof_powder_extinction [2022/11/03 15:08] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
+====== TOF_Powder_extinction ======
+Description: Extinction correction for TOF neutrons
+Comment: extinction for TOF powder data; value = mosaic block size in micron^2
+lambda is the TOF-dependent wavelength calculated in the Lobanov TOF absorption macro
+Contributed by: Pamela Whitfield
+   macro TOF_Powder_extinction(c, v) {
+   #m_argu c
+	  If_Prm_Eqn_Rpt(c, v, min = Val-.1; max = Val+.1; del 0.001)
+      local !xx = CeV(c,v) (lambda I_no_scale_pks / Get(cell_volume))^2;
+      local !Eb = 1/Sqrt(1 + xx);
+      local !El = If(xx < 1,
+- xx/2 + xx^2/4 - (5 xx^3)/48,
+      			Sqrt(2/Pi xx) (1 - 8/xx - 3/(128 xx^3) - 15/(1024 xx^5))
+      			);
+      scale_pks = 1/(Eb Sin(two_theta Deg_on_2)^2 + El Cos(two_theta Deg_on_2)^2);
+   }