Refs #17861 LoadILLTOF to calculate pulse intervals

Framework/DataHandling/inc/MantidDataHandling/LoadILLTOF.h

@@ -68,6 +68,7 @@ private:
   void initInstrumentSpecific();
   void addAllNexusFieldsAsProperties(std::string filename);
   void addEnergyToRun();
+  void addPulseInterval();
 
   int getDetectorElasticPeakPosition(const NeXus::NXInt &data);
   void loadTimeDetails(NeXus::NXEntry &entry);

Framework/DataHandling/src/LoadILLTOF.cpp

@@ -119,6 +119,7 @@ void LoadILLTOF::exec() {
                            calculatedDetectorElasticPeakPosition);
 
   addEnergyToRun();
+  addPulseInterval();
 
   // load the instrument from the IDF if it exists
   runLoadInstrument();
@@ -352,6 +353,35 @@ void LoadILLTOF::addEnergyToRun() {
   runDetails.addProperty<double>("Ei", ei, true); // overwrite
 }
 
+/**
+ * Calculate and add the pulse intervals for the run
+ */
+void LoadILLTOF::addPulseInterval() {
+  API::Run &runDetails = m_localWorkspace->mutableRun();
+  double pulseInterval;
+
+  if (m_instrumentName == "IN4") {
+    double fermiChopperSpeed = runDetails.getPropertyAsSingleValue("FC.rotation_speed");
+    double bkgChopper1Speed = runDetails.getPropertyAsSingleValue("BC1.rotation_speed");
+    double bkgChopper2Speed = runDetails.getPropertyAsSingleValue("BC2.rotation_speed");
+
+    if (std::abs(bkgChopper1Speed - bkgChopper2Speed) > 1) {
+      throw std::invalid_argument("Background choppers 1 and 2 have different speeds");
+    }
+
+    double n = fermiChopperSpeed / bkgChopper1Speed / 4;
+    pulseInterval = 60.0 / (2 * fermiChopperSpeed) * n;
+  } else if (m_instrumentName == "IN6") {
+    double fermiChopperSpeed = runDetails.getPropertyAsSingleValue("Fermi.rotation_speed");
+    double suppressorSpeed = runDetails.getPropertyAsSingleValue("Suppressor.rotation_speed");
+
+    double n = fermiChopperSpeed / suppressorSpeed;
+    pulseInterval = 60.0 / (2 * fermiChopperSpeed) * n;
+  }
+
+  runDetails.addProperty<double>("pulse_interval", pulseInterval);
+}
+
 /**
  * Gets the experimental Elastic Peak Position in the dectector
  * as the value parsed from the nexus file might be wrong.

Framework/DataHandling/test/LoadILLTOFTest.h

@@ -16,6 +16,10 @@ public:
   static LoadILLTOFTest *createSuite() { return new LoadILLTOFTest(); }
   static void destroySuite(LoadILLTOFTest *suite) { delete suite; }
 
+  void tearDown() override {
+    AnalysisDataService::Instance().clear();
+  }
+
   void testName() {
     LoadILLTOF loader;
     TS_ASSERT_EQUALS(loader.name(), "LoadILLTOF");
@@ -36,7 +40,7 @@ public:
    * This test only loads the Sample Data
    * The elastic peak is obtained on the fly from the sample data.
    */
-  void loadDataFile(const std::string dataFile, const int numberOfHistograms) {
+  MatrixWorkspace_sptr loadDataFile(const std::string dataFile, const int numberOfHistograms) {
     LoadILLTOF loader;
     loader.initialize();
     loader.setPropertyValue("Filename", dataFile);
@@ -53,12 +57,26 @@ public:
 
     TS_ASSERT_EQUALS(output2D->getNumberHistograms(), numberOfHistograms);
 
-    AnalysisDataService::Instance().clear();
+    return output2D;
   }
 
-  void test_IN4_load() { loadDataFile("ILL/IN4/084446.nxs", 397); }
-  void test_IN5_load() { loadDataFile("ILL/IN5/104007.nxs", 98305); }
-  void test_IN6_load() { loadDataFile("ILL/IN6/164192.nxs", 340); }
+  void test_IN4_load() {
+    MatrixWorkspace_sptr ws = loadDataFile("ILL/IN4/084446.nxs", 397);
+
+    double pulseInterval = ws->run().getLogAsSingleValue("pulse_interval");
+    TS_ASSERT_DELTA(0.003, pulseInterval, 1e-10);
+  }
+
+  void test_IN5_load() {
+    loadDataFile("ILL/IN5/104007.nxs", 98305);
+  }
+
+  void test_IN6_load() {
+    MatrixWorkspace_sptr ws = loadDataFile("ILL/IN6/164192.nxs", 340);
+
+    double pulseInterval = ws->run().getLogAsSingleValue("pulse_interval");
+    TS_ASSERT_DELTA(0.0060337892, pulseInterval, 1e-10);
+  }
 };
 
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