1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/*******************************************************************************
*
* McStas, neutron ray-tracing package
* Copyright 1997-2008, All rights reserved
* Risoe National Laboratory, Roskilde, Denmark
* Institut Laue Langevin, Grenoble, France
*
* Component: Mirror_Elliptic
*
* %I
* Written by: <a href="mailto:desert@drecam.cea.fr">Sylvain Desert</a>
* Date: 2007
* Origin: <a href="http://www-llb.cea.fr/">LLB</a>
* Modified by: E. Farhi, uniformize parameter names (Jul 2008)
*
* Elliptical mirror.
*
* %D
* Models an elliptical mirror. The reflectivity profile is given by a 2-column reflectivity free
* text file with format [q(Angs-1) R(0-1)]. The component is centered on the ellipse.
*
* Example: Mirror_Elliptic(reflect="supermirror_m3.rfl", focus=6.6e-4,
* interfocus = 8.2, yheight = 0.0002, zmin=-3.24, zmax=-1.49)
*
*
* %P
* INPUT PARAMETERS:
* yheight: [m] height of the mirror
* focus: [m] focal length (m)
* interfocus: [m] Distance between the two elliptical focal points
* zmin: [m] z-axis coordinate of ellipse start
* zmax: [m] z-axis coordinate of ellipse end
* reflect: [q(Angs-1) R(0-1)] (str) Reflectivity file name. Format
* R0: [1] Low-angle reflectivity
* Qc: [AA-1] Critical scattering vector
* alpha: [AA] Slope of reflectivity
* m: [1] m-value of material. Zero means completely absorbing.
* W: [AA-1] Width of supermirror cut-off
*
* Example instrument file FocalisationMirrors.instr is available in the examples/ folder.
*
* %E
*******************************************************************************/
DEFINE COMPONENT Mirror_Elliptic
SETTING PARAMETERS (string reflect=0, focus=6.6e-4,interfocus=8.2, yheight=2e-4, zmin=0, zmax=0,
R0=0.99, Qc=0.0219, alpha=6.07, m=1.0, W=0.003)
/* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */
SHARE
%{
#ifndef SIGN
#define SIGN(a) (a >= 0 ? (a == 0 ? 0 : 1) : -1)
#endif
%include "read_table-lib"
%include "ref-lib"
%}
DECLARE
%{
double beta1; /* ellipse parameters */
double alpha1;
double beta2; /* ellipse squared parameters */
double alpha2;
t_Table pTable;
int err;
%}
INITIALIZE
%{
if (reflect && strlen(reflect) && strcmp(reflect, "NULL") && strcmp(reflect,"0")) {
if (Table_Read(&pTable, reflect, 1) <= 0) /* read 1st block data from file into pTable */
exit(fprintf(stderr,"Mirror_Elliptic: %s: can not read file %s\n", NAME_CURRENT_COMP, reflect));
}
/* Calculation of ellipse parameters */
alpha1 = interfocus/2 +focus;
alpha2 = alpha1*alpha1;
beta2 = alpha2 - (interfocus*interfocus)/4;
beta1 = sqrt(beta2);
err = 0;
yheight/=2;
if(zmin==0&&zmax==0){
zmin = -alpha1;
zmax = alpha1;
}
else{
if(zmin>=zmax) exit(fprintf(stderr,"Mirror_Elliptic: %s: error definition zmin and zmax\n", NAME_CURRENT_COMP));
}
printf("Mirror_Elliptic: %s: alpha=%f alpha^2=%f beta=%f beta^2=%f\n",
NAME_CURRENT_COMP, alpha1,alpha2,beta1,beta2);
%}
TRACE
%{
double q, B;
double div,z1,x1,z2,x2;
double v;
double vx_2,vz_2;
int i=-1;
double oa,ob,ab,xa,za;
double angle;
double old_x;
double old_y;
double old_z;
double par[5] = {R0, Qc, alpha, m, W};
double a,b;
double delta;
/* First check if neutron has the right direction. */
if((vz != 0.0 && -z/vz >= 0) && x+beta1> 0)
{
i++;
old_z=z;
old_x=x;
old_y=y;
a=vx/vz;
b=x-a*z;
/* printf("\nx : %e / z : %f / y : %e\nvx : %e / vz : %e / vy : %e\na : %e / b : %f",x,z,y,vx,vz,a,b); */
/* Calculation of intersection with ellipse */
delta = sqrt(4*(a*a*b*b-(a*a+beta2/alpha2)*(b*b-beta2)));
/* printf("\nDELTA : %e",delta); */
z1 = (-2*a*b - delta)/(2*(a*a+beta2/alpha2));
z2 = (-2*a*b + delta)/(2*(a*a+beta2/alpha2));
x1 = a*z1+b;
x2 = a*z2+b;
/* printf("\nx1 : %f / z1 : %f\nx2 : %f / z2 : %f\n",x1,z1,x2,z2); */
/* Choose the right result */
if((z1>z2)&&(fabs(z1)<alpha1)){
x=SIGN(x1)*beta1*sqrt(1-z1*z1/alpha2);
z=z1;
}
else{
if(fabs(z2)<alpha1){
x=SIGN(x2)*beta1*sqrt(1-z2*z2/alpha2);
z=z2;
}
else{
printf("Mirror_Elliptic: %s: WARNING: Error in the coordinates calculation (Absorb)\n", NAME_CURRENT_COMP);
ABSORB;
}
}
if(fabs(x-a*z-b)>0.001){
#pragma acc atomic
err = err + 1;
printf("Mirror_Elliptic: %s: x=%e z=%f X=%f (Absorb)",NAME_CURRENT_COMP,x,z,a*z+b);
ABSORB;
}
/* y calculation */
y+=vy*(z-old_z)/vz;
/*reflection*/
if(x<0 && fabs(y)<=yheight && z>=zmin && z<=zmax){
/*reflection angle in the plane xz*/
div = -atan(vx/vz);
angle = -atan((beta2*z)/(alpha2*x));
/*vx and vz calculation after reflection*/
v=sqrt(vx*vx+vz*vz);
vz = v*cos(2*angle+div);
vx = v*sin(2*angle+div);
/*
printf("reflection2D :\nv: %e / angle (tangeante) : %f / div : %f / incidence : %f\n",v,angle,div,2*angle+div);
printf("vx : %f /vz : %f\n",vx,vz);
*/
/*incidence angle in 3D*/
ob = sqrt((old_x-x)*(old_x-x)+(old_z-z)*(old_z-z));
xa = x-ob*cos(div+angle)*sin(angle);
za = z-ob*cos(div+angle)*cos(angle);
oa = sqrt((old_x-xa)*(old_x-xa)+(old_z-za)*(old_z-za));
ob = sqrt((old_x-x)*(old_x-x)+(old_y-y)*(old_y-y)+(old_z-z)*(old_z-z));
ab = sqrt((xa-x)*(xa-x)+(old_y-y)*(old_y-y)+(za-z)*(za-z));
angle = acos((-ab*ab-ob*ob+oa*oa)/(2*ab*ob));
/* printf("3D :\nxa : %f / za : %f\noa : %f / ob : %f / ab : %f\nangle : %f / v : %e\n",xa,za,oa,ob,ab,angle,v); */
v=sqrt(vx*vx+vy*vy+vz*vz);
q = fabs(2*sin(angle)*v*V2Q);
/* Reflectivity (see component Guide). */
if (reflect && strlen(reflect) && strcmp(reflect,"NULL") && strcmp(reflect,"0"))
TableReflecFunc(q, &pTable, &B);
else {
StdReflecFunc(q, par, &B);
}
if (B <= 0) { ABSORB; }
else p *= B;
}
else ABSORB;
SCATTER;
}
else{
ABSORB;
}
%}
FINALLY
%{
if(err!=0){
fprintf(stderr,"Mirror_Elliptic: %s: WARNING : %d neutrons absorbed for inadapted divergence !\n", NAME_CURRENT_COMP, err);
}
%}
MCDISPLAY
%{
double xi,zi,xf,zf,delta_z;
delta_z = (zmax-zmin)/99;
xi=-beta1*sqrt(1-zmin*zmin/alpha2);
line(xi,-yheight,zmin,xi,yheight,zmin);
zi=zmin;
/* printf("delta_z : %f / xi : %f / zi : %f\n",delta_z,xi,zi); */
do{
zf = zi + delta_z;
xf=-beta1*sqrt(1-zf*zf/alpha2);
line(xi,yheight,zi,xf,yheight,zf);
line(xf,yheight,zf,xf,-yheight,zf);
line(xf,-yheight,zf,xi,-yheight,zi);
xi=xf;
zi=zf;
} while(zf<=zmax);
%}
END
|
