Move the constants to an internal variable

corsika/detail/modules/radio/CoREAS.inl

@@ -50,8 +50,7 @@ namespace corsika {
       auto const thinningWeight{step.getParticlePre().getWeight()};
 
       // constants for electric field vector calculation
-      auto const constants_{(charge_ / (4 * M_PI) / (constants::epsilonZero) /
-                            constants::c) * thinningWeight};
+      auto const constants_{charge_ * emConstant_ * thinningWeight};
 
       // set threshold for application of ZHS-like approximation.
       const double approxThreshold_{1.0e-3};

corsika/detail/modules/radio/ZHS.inl

@@ -44,7 +44,7 @@ namespace corsika {
       // get thinning weight
       auto const thinningWeight{step.getParticlePre().getWeight()};
 
-      auto const constants{(charge / (4 * M_PI) / (constants::epsilonZero) / constants::c) * thinningWeight};
+      auto const constants{charge * emConstant_ * thinningWeight};
 
       // we loop over each antenna in the collection
       for (auto& antenna : antennas_.getAntennas()) {

corsika/modules/radio/CoREAS.hpp

@@ -47,6 +47,8 @@ namespace corsika {
      */
     template <typename Particle>
     ProcessReturn simulate(Step<Particle> const& step);
+    static constexpr auto emConstant_{1.0 / (4.0 * M_PI) / (constants::epsilonZero) /
+                                      constants::c};
 
     using Base =
         RadioProcess<TRadioDetector, CoREAS<TRadioDetector, TPropagator>, TPropagator>;

corsika/modules/radio/ZHS.hpp

@@ -49,6 +49,8 @@ namespace corsika {
      */
     template <typename Particle>
     ProcessReturn simulate(Step<Particle> const& step) const;
+    static constexpr auto emConstant_{1.0 / (4.0 * M_PI) / (constants::epsilonZero) /
+                                      constants::c};
 
   private:
     using Base =