The types rf_phasor and rf_phasor_8

For the probe and the probe_8 we refer to section 4.2.2.1.

The probe contains an instance of the type rf_phasor

  type rf_phasor
     real(dp) x(2)
     real(dp) om
  end type rf_phasor

and probe_8 contains an instance of the type rf_phasor_8

  type rf_phasor_8
     type(real_8)  x(2)
     type(real_8) om
  end type rf_phasor_8

For example, we initialize a probe (without spin) as follows:

    Ray=x
   ray%ac%om=0.001d0
   ray%ac%x(1)=1.d0    ! fake phasor 
   ray%ac%x(2)=0.d0    !   fake phasor 

The rf_phasor contains a phasor (a clock) which rotates according to a variable D_AC stored on the integration node. The frequency of the rotation is ``om''.

In PTC the following code is used:

  beta0=>C%PARENT_FIBRE%beta0
   xt = cos(XS%AC%om * c%DS_AC/beta0) *XS%AC%X(1) + sin(XS%AC%om * c%DS_AC/beta0) *XS%AC%X(2)
   XS%AC%X(2) = -sin(XS%AC%om * c%DS_AC/beta0) *XS%AC%X(1) + cos(XS%AC%om * c%DS_AC/beta0) *XS%AC%X(2)
   XS%AC%X(1) = xt

D_AC for an ordinary lattice is the length along the ``ideal'' orbit. Obviously a user can modify this. It is clear that the phasor, like the spin, simply rotates around the ring and is not influenced by other variables. This can only be correct for slow modulation: N.B. real time is not used.