Exemplo n.º 1
0
    def generator(self, Emin=1., Emax=1000., Exp=False,  sphi=0., stheta=pi, deltasource=0):
      
        '''Generates randomly a photon going onto the xtal.
        Exp is the powerlaw spectral index -2.1 for Crab '''
       
        # Defines the crystal angles using the angular coordinate of the  
        # reciprocal lattice vector g. The same crystal angles (with -sign)
        # will be also appplied to the generated photon.
        
        l = math.sqrt(self.photon.r[0]**2 + self.photon.r[1]**2)
        #print "divergenza",self.photon.r[0], self.photon.r[1], l, self.divergence_stheta(l, deltasource)
        #print "stheta", stheta
        #stheta = stheta - self.divergence_stheta(l, deltasource)
        #sphi = self.divergence_sphi(self.photon.r)
        #print "stheta", stheta
        
        # Set the photon intensity equal to 1. This function generate a probability
        # for the photon, then it will be multplied by the requested intensity set 
        # in the macro
        if self.photon.i !=1: self.photon.i=1.
        # wavevector definition from source angular parameters
        # stheta = pi and sphi = 0 means on-axis source while
        # off-axis source is simply obtained by changing stheta.
        # the k value is related to the energy from the relation k = 2 pi/lambda
        # is the erandom function that make the k from module 1 to the correct module 
        # indeed erandom set the energy and follow that automatically k is set.
        # Now photon.k has module 1, erandom will give the right normalization. 

        self.photon.k=Physics.makenormalvec(sphi, stheta)
        # Energy calculation (powerlaw if Exp is False)
        self.erandom((Emin, Emax), Exp=Exp)
Exemplo n.º 2
0
    def generator(self, Emin=1., Emax=1000., Exp=False,  sphi=0., stheta=pi):
        '''Generates randomly a photon that will go on to xtal.
        Exp is the powerlaw spectral index (-2.1 for the Crab Nebula).
        '''
        theta, phi = pi/2-self.xtal.gtheta, self.xtal.gphi
        # lambda functions #
        drag_out_xtal = lambda x: array(x) + array(self.xtal.r)
        rot_out_xtal = lambda x: Physics.rot(x, (('y', -theta), ('z', -phi)))

        # Puts a photon an EPSILON under the xtal surface in a random 2D point
        random_pos_on_surface=[uniform(-x/2., x/2.) for x in self.xtal.dim[:2]]
        random_pos_on_surface.append(-EPSILON)
        self.photon.r=random_pos_on_surface

        # The photon position in observer reference frame (rotation + translation)
        self.photon.r=rot_out_xtal(self.photon.r)
        self.photon.r=drag_out_xtal(self.photon.r)
        if self.photon.i !=1: self.photon.i=1.
        # wavevector definition from source angular parameters
        self.photon.k=Physics.makenormalvec(sphi, stheta)
        # Energy calculation (powerlaw if Exp is False)
        self.erandom((Emin, Emax), Exp=Exp)