fixing problems in Autophasing algorithm with DC guns

src/Algorithms/CavityAutophaser.cpp

@@ -52,7 +52,6 @@ double CavityAutophaser::getPhaseAtMaxEnergy(const Vector_t &R,
     if (!apVeto) {
         double initialEnergy = Util::getEnergy(P, itsReference_m.getM()) * 1e-6;
         double AstraPhase    = 0.0;
-        double initialPhase  = guessCavityPhase(t + tErr);
         double designEnergy  = element->getDesignEnergy();
 
         if (amplitude < 0.0) {
@@ -60,6 +59,8 @@ double CavityAutophaser::getPhaseAtMaxEnergy(const Vector_t &R,
             element->setAmplitudem(amplitude);
         }
 
+        double initialPhase  = guessCavityPhase(t + tErr);
+
         if (amplitude == 0.0 && designEnergy <= 0.0) {
             throw OpalException("CavityAutophaser::getPhaseAtMaxEnergy()",
                                 "neither amplitude or design energy given to cavity " + element->getName());
@@ -245,11 +246,9 @@ double CavityAutophaser::track(Vector_t R,
                                                             itsReference_m.getQ(),
                                                             itsReference_m.getM() * 1e-6,
 							    out);
-    double finalMomentum = pe.first;
     rfc->setPhasem(initialPhase);
 
-    double finalGamma = sqrt(1.0 + finalMomentum * finalMomentum);
-    double finalKineticEnergy = (finalGamma - 1.0) * itsReference_m.getM() * 1e-6;
+    double finalKineticEnergy = Util::getEnergy(pe.first, itsReference_m.getM() * 1e-6);
 
     return finalKineticEnergy;
 }
\ No newline at end of file

src/Classic/AbsBeamline/RFCavity.cpp

@@ -35,15 +35,6 @@ extern Inform *gmsg;
 
 using namespace std;
 
-class NegativeMomentumError: public GeneralClassicException
-{
-public:
-    NegativeMomentumError(const std::string &where,
-                          const std::string &what):
-        GeneralClassicException(where, what)
-    { }
-};
-
 // Class RFCavity
 // ------------------------------------------------------------------------
 
@@ -619,6 +610,8 @@ ElementBase::ElementType RFCavity::getType() const {
 double RFCavity::getAutoPhaseEstimateFallback(double E0, double t0, double q, double mass) {
     const double dt = 1e-13;
     const double p0 = Util::getP(E0, mass);
+    const double origPhase =getPhasem();
+
     double dphi = pi / 18;
 
     double phi = 0.0;
@@ -652,6 +645,7 @@ double RFCavity::getAutoPhaseEstimateFallback(double E0, double t0, double q, do
             << phimax * Physics::rad2deg << " deg \n"
             << "Ekin= " << Emax << " MeV" << setprecision(prevPrecision) << endl);
 
+    setPhasem(origPhase);
     return phimax;
 }
 
@@ -815,9 +809,6 @@ pair<double, double> RFCavity::trackOnAxisParticle(const double &p0,
             applyToReferenceParticle(z, p, t + 0.5 * dt, Ef, Bf);
         }
         integrator.kick(z, p, Ef, Bf, dt);
-        if (z[2] < zbegin)
-            throw NegativeMomentumError("RFCavit::trackOnAxisParticle",
-                                        "registered negative momentum");
 
         dz = 0.5 * p(2) / sqrt(1.0 + dot(p, p)) * cdt;
         z /= cdt;

[adelmann]

Looks like the DC gun tests are broken now

[kraus]

Ok, that's fixed now.