#include "scattering.h" #include "quantum_efficiency.h" #include #include #include #include #include "optics.h" #include "sno.h" #include /* for size_t */ #include /* for exit() */ #include /* for fprintf() */ #include /* for gsl_strerror() */ #include "pdg.h" #include #include static double xlo = -1.0; static double xhi = 1.0; static size_t nx = 1000; static double ylo = 0.0; static double yhi = MAX_THETA0; static size_t ny = 1000; static double *x; static double *y; static double *z; static gsl_spline2d *spline; static gsl_interp_accel *xacc; static gsl_interp_accel *yacc; static double x2lo = 0.0; static double x2hi = 1.0; static size_t nx2 = 1000; static double *x2; static double *y2; static gsl_spline *spline2; static gsl_interp_accel *xacc2; static double prob_scatter(double wavelength, void *params) { /* Calculate the number of photons emitted per unit solid angle per cm at * an angle `theta` for a particle travelling with velocity `beta` with an * angular distribution of width `theta0`. */ double qe, delta, index; double beta_cos_theta = ((double *) params)[0]; double beta_sin_theta_theta0 = ((double *) params)[1]; qe = get_quantum_efficiency(wavelength); index = get_index_snoman_d2o(wavelength); delta = (1.0/index - beta_cos_theta)/beta_sin_theta_theta0; return qe*exp(-pow(delta,2)/2.0)/pow(wavelength,2)*1e7/sqrt(2*M_PI); } static double prob_scatter2(double wavelength, void *params) { /* Calculate the number of photons emitted per per cm for a particle * travelling with velocity `beta`. */ double qe, index; double beta = ((double *) params)[0]; qe = get_quantum_efficiency(wavelength); index = get_index_snoman_d2o(wavelength); return 2*M_PI*FINE_STRUCTURE_CONSTANT*(1-(1/(beta*beta*index*index)))*qe/pow(wavelength,2)*1e7; } void init_interpolation(void) { size_t i, j; double params[2]; double result, error; size_t nevals; int status; gsl_integration_cquad_workspace *w; gsl_function F; x = malloc(nx*sizeof(double)); y = malloc(ny*sizeof(double)); z = malloc(nx*ny*sizeof(double)); spline = gsl_spline2d_alloc(gsl_interp2d_bilinear, nx, ny); xacc = gsl_interp_accel_alloc(); yacc = gsl_interp_accel_alloc(); for (i = 0; i < nx; i++) { x[i] = xlo + (xhi-xlo)*i/(nx-1); } for (i = 0; i < ny; i++) { y[i] = ylo + (yhi-ylo)*i/(ny-1); } w = gsl_integration_cquad_workspace_alloc(100); F.function = &prob_scatter; F.params = params; for (i = 0; i < nx; i++) { for (j = 0; j < ny; j++) { params[0] = x[i]; params[1] = y[j]; status = gsl_integration_cquad(&F, 200, 800, 0, 1e-2, w, &result, &error, &nevals); if (status) { fprintf(stderr, "error integrating photon angular distribution: %s\n", gsl_strerror(status)); exit(1); } gsl_spline2d_set(spline, z, i, j, result); } } gsl_spline2d_init(spline, x, y, z, nx, ny); x2 = malloc(nx2*sizeof(double)); y2 = malloc(nx2*sizeof(double)); spline2 = gsl_spline_alloc(gsl_interp_linear, nx2); xacc2 = gsl_interp_accel_alloc(); for (i = 0; i < nx2; i++) { x2[i] = x2lo + (x2hi-x2lo)*i/(nx2-1); } F.function = &prob_scatter2; F.params = params; for (i = 0; i < nx2; i++) { params[0] = x2[i]; status = gsl_integration_cquad(&F, 200, 800, 0, 1e-2, w, &result, &error, &nevals); if (status) { fprintf(stderr, "error integrating photon angular distribution: %s\n", gsl_strerror(status)); exit(1); } y2[i] = result; } gsl_spline_init(spline2, x2, y2, nx2); gsl_integration_cquad_workspace_free(w); } double get_probability(double beta, double cos_theta, double theta0) { double sin_theta; /* Technically this isn't defined up to a sign, but it doesn't matter since * we are going to square it everywhere. */ sin_theta = sqrt(1-pow(cos_theta,2)); return gsl_spline2d_eval(spline, beta*cos_theta, beta*sin_theta*theta0, xacc, yacc)/(theta0*sin_theta); } double get_probability2(double beta) { return gsl_spline_eval(spline2, beta, xacc2); } void free_interpolation(void) { free(x); free(y); free(z); gsl_spline2d_free(spline); gsl_interp_accel_free(xacc); gsl_interp_accel_free(yacc); } n69'>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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257