#ifndef ALI_TPC_EX_B_TWIST_H #define ALI_TPC_EX_B_TWIST_H /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * * See cxx source for full Copyright notice */ // _________________________________________________________________ // // Begin_Html //
// It assumes a homogeneous magnetic and electric field. The calculations performed // within this class can be written in a compact form as well (compare notes of Jim Thomas) //
// The inputs to this class are the twist angles in the x and y plane ($\theta_x,\theta_y$) // in cartesian coordinates. They can be set via the member functions SetXTwist and SetYTwist. // End_Html // // Begin_Macro(source) // { // gROOT->SetStyle("Plain"); gStyle->SetPalette(1); // TCanvas *c2 = new TCanvas("c2","c2",500,300); // AliTPCExBTwist twist; // twist.SetXTwist(0.001); // x angle in [rad] // twist.SetXTwist(0.0005); // y angle in [rad] // twist.SetOmegaTauT1T2(0.32,1,1); // twist.CreateHistoDRPhiinXY(1.)->Draw("surf2"); // A side // return c2; // } // End_Macro // // Begin_Html //
// Date: 27/04/2010
// Authors: Jim Thomas, Magnus Mager, Stefan Rossegger
// End_Html
// _________________________________________________________________
#include "AliTPCCorrection.h"
class AliTPCExBTwist : public AliTPCCorrection {
public:
AliTPCExBTwist();
virtual ~AliTPCExBTwist();
// initialization and update functions
virtual void Init();
virtual void Update(const TTimeStamp &timeStamp);
// common setters and getters for ExB
virtual void SetOmegaTauT1T2(Float_t omegaTau,Float_t t1,Float_t t2) {
fT1=t1; fT2=t2;
const Float_t wt1=t1*omegaTau; fC1=wt1/(1.+wt1*wt1);
const Float_t wt2=t2*omegaTau; fC2=wt2*wt2/(1.+wt2*wt2);
};
void SetC1C2(Float_t c1,Float_t c2) {fC1=c1;fC2=c2;} // CAUTION: USE WITH CARE
Float_t GetC1() const {return fC1;}
Float_t GetC2() const {return fC2;}
// setters and getters for twist
void SetXTwist(Float_t xTwist) {fXTwist=xTwist;}
void SetYTwist(Float_t yTwist) {fYTwist=yTwist;}
Float_t GetXTwist() const {return fXTwist;}
Float_t GetYTwist() const {return fYTwist;}
virtual void Print(const Option_t* option="") const;
protected:
virtual void GetCorrection(const Float_t x[],const Short_t roc,Float_t dx[]);
private:
Float_t fC1; // coefficient C1 (compare Jim Thomas's notes for definitions)
Float_t fC2; // coefficient C2 (compare Jim Thomas's notes for definitions)
Float_t fXTwist; // Twist of E to B field in X-Z [rad]
Float_t fYTwist; // Twist of E to B field in Y-Z [rad]
ClassDef(AliTPCExBTwist,1);
};
#endif