[u/mrichter/AliRoot.git] / RICH / AliRICHSegResV0.cxx

#include "AliRICHSegResV0.h"
#include "AliRun.h"
#include "TParticle.h"
#include "TMath.h"
#include "TRandom.h"


ClassImp(AliRICHsegmentation)
ClassImp(AliRICHresponse)	
//___________________________________________
ClassImp(AliRICHsegmentationV0)

void AliRICHsegmentationV0::Init(AliRICHchamber* Chamber)
{
    fNpx=(Int_t) (Chamber->ROuter()/fDpx+1);
    fNpy=(Int_t) (Chamber->ROuter()/fDpy+1);
}


Float_t AliRICHsegmentationV0::GetAnod(Float_t xhit)
{
    Float_t wire= (xhit>0)? Int_t(xhit/fWireD)+0.5:Int_t(xhit/fWireD)-0.5;
    return fWireD*wire;
}

void AliRICHsegmentationV0::SetPADSIZ(Float_t p1, Float_t p2)
{
    fDpx=p1;
    fDpy=p2;
}
void AliRICHsegmentationV0::GetPadIxy(Float_t x, Float_t y, Int_t &ix, Int_t &iy)
{
//  returns pad coordinates (ix,iy) for given real coordinates (x,y)
//
    ix = (x>0)? Int_t(x/fDpx)+1 : Int_t(x/fDpx);
    iy = (y>0)? Int_t(y/fDpy)+1 : Int_t(y/fDpy);
    if (iy >  fNpy) iy= fNpy;
    if (iy < -fNpy) iy=-fNpy;
    if (ix >  fNpx) ix= fNpx;
    if (ix < -fNpx) ix=-fNpx;
}
void AliRICHsegmentationV0::
GetPadCxy(Int_t ix, Int_t iy, Float_t &x, Float_t &y)
{
//  returns real coordinates (x,y) for given pad coordinates (ix,iy)
//
    x = (ix>0) ? Float_t(ix*fDpx)-fDpx/2. : Float_t(ix*fDpx)-fDpx/2.;
    y = (iy>0) ? Float_t(iy*fDpy)-fDpy/2. : Float_t(iy*fDpy)-fDpy/2.;
}

void AliRICHsegmentationV0::
FirstPad(Float_t xhit, Float_t yhit, Float_t dx, Float_t dy)
{
    //
    // Find the wire position (center of charge distribution)
    Float_t x0a=GetAnod(xhit);
    //
    // and take fNsigma*sigma around this center
    Float_t x01=x0a  - dx;
    Float_t x02=x0a  + dx;
    Float_t y01=yhit - dy;
    Float_t y02=yhit + dy;
    //
    // find the pads over which the charge distributes
    GetPadIxy(x01,y01,fixmin,fiymin);
    GetPadIxy(x02,y02,fixmax,fiymax);    
    // 
    // Set current pad to lower left corner
    fix=fixmin;
    fiy=fiymin;
    GetPadCxy(fix,fiy,fx,fy);
}

void AliRICHsegmentationV0::NextPad()
{
    // 
    // Step to next pad in integration region
    if (fix != fixmax) {
	fix++;
    } else if (fiy != fiymax) {
	fix=fixmin;
	fiy++;
    } else {
	printf("\n Error: Stepping outside integration region\n ");
    }
    GetPadCxy(fix,fiy,fx,fy);
}

Int_t AliRICHsegmentationV0::MorePads()
    
//
// Are there more pads in the integration region
{
    if (fix == fixmax && fiy == fiymax) {
	return 0;
    } else {
	return 1;
	
    }
}

void AliRICHsegmentationV0::SigGenInit(Float_t x,Float_t y,Float_t)
{
//
//  Initialises pad and wire position during stepping
    fxt =x;
    fyt =y;
    GetPadIxy(x,y,fixt,fiyt);
    fiwt=Int_t(x/fWireD)+1;
    
}

Int_t AliRICHsegmentationV0::SigGenCond(Float_t x,Float_t y,Float_t)
{
//
//  Signal will be generated if particle crosses pad boundary or
//  boundary between two wires. 
    Int_t ixt, iyt;
    GetPadIxy(x,y,ixt,iyt);
    Int_t iwt=Int_t(x/fWireD)+1;
    
    if ((ixt != fixt) || (iyt !=fiyt) || (iwt != fiwt)) {
	return 1;
    } else {
	return 0;
    }
}
void AliRICHsegmentationV0::
IntegrationLimits(Float_t& x1,Float_t& x2,Float_t& y1, Float_t& y2)
{
    x1=fxt-fx-fDpx/2.;
    x2=x1+fDpx;
    y1=fyt-fy-fDpy/2.;
    y2=y1+fDpy;    
    
}

void AliRICHsegmentationV0::
Neighbours(Int_t iX, Int_t iY, Int_t* Nlist, Int_t Xlist[7], Int_t Ylist[7])
{
//Is used for the cluster finder, include diagonal elements
    
    *Nlist=4;Xlist[0]=Xlist[1]=iX;Xlist[2]=iX-1;Xlist[3]=iX+1;
    Ylist[0]=iY-1;Ylist[1]=iY+1;Ylist[2]=Ylist[3]=iY;
}

void AliRICHsegmentationV0::
FitXY(AliRICHRecCluster* ,TClonesArray* )
    // Default : Centre of gravity method
{
    ;
}


//___________________________________________
ClassImp(AliRICHresponseV0)	
    Float_t AliRICHresponseV0::IntPH(Float_t eloss)
{
    // Get number of electrons and return charge
    
    Int_t nel;
//E9/26=magic number should parameter
    nel= Int_t(eloss*1.e9/26.);
    Float_t charge=0;
    if (nel == 0) nel=1;
    for (Int_t i=1;i<=nel;i++) {
	charge -= fChslope*TMath::Log(gRandom->Rndm());    
    }
    return charge;
}
// -------------------------------------------
Float_t AliRICHresponseV0::IntXY(AliRICHsegmentation * segmentation)
{
    
    const Float_t invpitch = 1/fPitch;
    Float_t response;
//
//  Integration limits defined by segmentation model
//  
    
    Float_t xi1, xi2, yi1, yi2;
    segmentation->IntegrationLimits(xi1,xi2,yi1,yi2);
    xi1=xi1*invpitch;
    xi2=xi2*invpitch;
    yi1=yi1*invpitch;
    yi2=yi2*invpitch;
    
    //
// The Mathieson function 
    Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
    Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
    
    Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
    Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
    
    response=4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1));

    return response;       
    
}
//___________________________________________
Int_t AliRICHresponseV0::FeedBackPhotons(Float_t source[3], Float_t qtot)
{
  //
  // Generate FeedBack photons
  //
  Int_t j, ipart, nt;
    
  //Probability of feedback
  Float_t fAlphaFeed=0.05;
    
  Int_t sNfeed=0;
  
  // Local variables 
  Float_t cthf, ranf[2], phif, enfp = 0, sthf, weight;
  Int_t i, ifeed;
  Float_t e1[3], e2[3], e3[3];
  Float_t vmod, uswop;
  Float_t fp, random;
  Float_t dir[3], phi;
  Int_t nfp;
  Float_t pol[3], mom[3];
  TLorentzVector position;
  //
  // Determine number of feedback photons

  //  Get weight of current particle
  TParticle *current = (TParticle*) 
    (*gAlice->Particles())[gAlice->CurrentTrack()];
    
  ifeed = Int_t(current->GetWeight()/100+0.5);
  ipart = gMC->TrackPid();
  fp = fAlphaFeed * qtot;
  nfp = gRandom->Poisson(fp);
  
  // This call to fill the time of flight
  gMC->TrackPosition(position);
  //
  // Generate photons
  for (i = 0; i <nfp; ++i) {
	
    // Direction
    gMC->Rndm(ranf, 2);
    cthf = ranf[0] * 2 - 1.;
    if (cthf < 0)  continue;
    sthf = TMath::Sqrt((1 - cthf) * (1 + cthf));
    phif = ranf[1] * 2 * TMath::Pi();
    //
    gMC->Rndm(&random, 1);
    if (random <= .57) {
      enfp = 7.5e-9;
    } else if (random <= .7) {
      enfp = 6.4e-9;
    } else {
      enfp = 7.9e-9;
    }

    dir[0] = sthf * TMath::Sin(phif);
    dir[1] = cthf;
    dir[2] = sthf * TMath::Cos(phif);
    gMC->Gdtom(dir, mom, 2);
    mom[0]*=enfp;
    mom[1]*=enfp;
    mom[2]*=enfp;
    
    // Polarisation
    e1[0] = 0;
    e1[1] = -dir[2];
    e1[2] = dir[1];
    
    e2[0] = -dir[1];
    e2[1] = dir[0];
    e2[2] = 0;
    
    e3[0] = dir[1];
    e3[1] = 0;
    e3[2] = -dir[0];
    
    vmod=0;
    for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
    if (!vmod) for(j=0;j<3;j++) {
      uswop=e1[j];
      e1[j]=e3[j];
      e3[j]=uswop;
    }
    vmod=0;
    for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
    if (!vmod) for(j=0;j<3;j++) {
      uswop=e2[j];
      e2[j]=e3[j];
      e3[j]=uswop;
    }
    
    vmod=0;
    for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
    vmod=TMath::Sqrt(1/vmod);
    for(j=0;j<3;j++) e1[j]*=vmod;
    
    vmod=0;
    for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
    vmod=TMath::Sqrt(1/vmod);
    for(j=0;j<3;j++) e2[j]*=vmod;
    
    gMC->Rndm(ranf, 1);
    phi = ranf[0] * 2 * TMath::Pi();
    for(j=0;j<3;j++) pol[j]=e1[j]*TMath::Sin(phi)+e2[j]*TMath::Cos(phi);
    gMC->Gdtom(pol, pol, 2);
    
    // Put photon on the stack and label it as feedback (51, 52) 
    ++sNfeed;
    if (ipart == 50000050 && ifeed != 50000052) {
      weight = 5000;
    } else {
      weight = 5000;
    }
    gAlice->SetTrack(1, gAlice->CurrentTrack(), gMC->PDGFromId(50),
		     mom,source,pol,position[3],
		     "Cherenkov", nt, weight);
  }
  return(sNfeed);
}
Commit	Line	Data
ddae0931	1	#include "AliRICHSegResV0.h"
	2	#include "AliRun.h"
	3	#include "TParticle.h"
	4	#include "TMath.h"
	5	#include "TRandom.h"
	6
	7
	8	ClassImp(AliRICHsegmentation)
	9	ClassImp(AliRICHresponse)
	10	//___________________________________________
	11	ClassImp(AliRICHsegmentationV0)
	12
	13	void AliRICHsegmentationV0::Init(AliRICHchamber* Chamber)
	14	{
	15	fNpx=(Int_t) (Chamber->ROuter()/fDpx+1);
	16	fNpy=(Int_t) (Chamber->ROuter()/fDpy+1);
	17	}
	18
	19
	20	Float_t AliRICHsegmentationV0::GetAnod(Float_t xhit)
	21	{
	22	Float_t wire= (xhit>0)? Int_t(xhit/fWireD)+0.5:Int_t(xhit/fWireD)-0.5;
	23	return fWireD*wire;
	24	}
	25
	26	void AliRICHsegmentationV0::SetPADSIZ(Float_t p1, Float_t p2)
	27	{
	28	fDpx=p1;
	29	fDpy=p2;
	30	}
	31	void AliRICHsegmentationV0::GetPadIxy(Float_t x, Float_t y, Int_t &ix, Int_t &iy)
	32	{
	33	// returns pad coordinates (ix,iy) for given real coordinates (x,y)
	34	//
	35	ix = (x>0)? Int_t(x/fDpx)+1 : Int_t(x/fDpx);
	36	iy = (y>0)? Int_t(y/fDpy)+1 : Int_t(y/fDpy);
	37	if (iy > fNpy) iy= fNpy;
	38	if (iy < -fNpy) iy=-fNpy;
	39	if (ix > fNpx) ix= fNpx;
	40	if (ix < -fNpx) ix=-fNpx;
	41	}
	42	void AliRICHsegmentationV0::
	43	GetPadCxy(Int_t ix, Int_t iy, Float_t &x, Float_t &y)
	44	{
	45	// returns real coordinates (x,y) for given pad coordinates (ix,iy)
	46	//
	47	x = (ix>0) ? Float_t(ixfDpx)-fDpx/2. : Float_t(ixfDpx)-fDpx/2.;
	48	y = (iy>0) ? Float_t(iyfDpy)-fDpy/2. : Float_t(iyfDpy)-fDpy/2.;
	49	}
	50
	51	void AliRICHsegmentationV0::
	52	FirstPad(Float_t xhit, Float_t yhit, Float_t dx, Float_t dy)
	53	{
	54	//
	55	// Find the wire position (center of charge distribution)
	56	Float_t x0a=GetAnod(xhit);
	57	//
	58	// and take fNsigma*sigma around this center
	59	Float_t x01=x0a - dx;
	60	Float_t x02=x0a + dx;
	61	Float_t y01=yhit - dy;
	62	Float_t y02=yhit + dy;
	63	//
	64	// find the pads over which the charge distributes
65	GetPadIxy(x01,y01,fixmin,fiymin);
66	GetPadIxy(x02,y02,fixmax,fiymax);
67	//
68	// Set current pad to lower left corner
69	fix=fixmin;
70	fiy=fiymin;
71	GetPadCxy(fix,fiy,fx,fy);
72	}
73
74	void AliRICHsegmentationV0::NextPad()
75	{
76	//
77	// Step to next pad in integration region
78	if (fix != fixmax) {
79	fix++;
80	} else if (fiy != fiymax) {
81	fix=fixmin;
82	fiy++;
83	} else {
84	printf("\n Error: Stepping outside integration region\n ");
85	}
86	GetPadCxy(fix,fiy,fx,fy);
87	}
88
89	Int_t AliRICHsegmentationV0::MorePads()
90
91	//
92	// Are there more pads in the integration region
93	{
94	if (fix == fixmax && fiy == fiymax) {
95	return 0;
96	} else {
97	return 1;
98
99	}
100	}
101
102	void AliRICHsegmentationV0::SigGenInit(Float_t x,Float_t y,Float_t)
103	{
104	//
105	// Initialises pad and wire position during stepping
106	fxt =x;
107	fyt =y;
108	GetPadIxy(x,y,fixt,fiyt);
109	fiwt=Int_t(x/fWireD)+1;
110
111	}
112
113	Int_t AliRICHsegmentationV0::SigGenCond(Float_t x,Float_t y,Float_t)
114	{
115	//
116	// Signal will be generated if particle crosses pad boundary or
117	// boundary between two wires.
118	Int_t ixt, iyt;
119	GetPadIxy(x,y,ixt,iyt);
120	Int_t iwt=Int_t(x/fWireD)+1;
121
122	if ((ixt != fixt) \|\| (iyt !=fiyt) \|\| (iwt != fiwt)) {
123	return 1;
124	} else {
125	return 0;
126	}
127	}
128	void AliRICHsegmentationV0::
129	IntegrationLimits(Float_t& x1,Float_t& x2,Float_t& y1, Float_t& y2)
130	{
131	x1=fxt-fx-fDpx/2.;
132	x2=x1+fDpx;
133	y1=fyt-fy-fDpy/2.;
134	y2=y1+fDpy;
135
136	}
137
138	void AliRICHsegmentationV0::
139	Neighbours(Int_t iX, Int_t iY, Int_t* Nlist, Int_t Xlist[7], Int_t Ylist[7])
140	{
141	//Is used for the cluster finder, include diagonal elements
142
143	*Nlist=4;Xlist[0]=Xlist[1]=iX;Xlist[2]=iX-1;Xlist[3]=iX+1;
144	Ylist[0]=iY-1;Ylist[1]=iY+1;Ylist[2]=Ylist[3]=iY;
145	}
146
147	void AliRICHsegmentationV0::
148	FitXY(AliRICHRecCluster* ,TClonesArray* )
149	// Default : Centre of gravity method
150	{
151	;
152	}
153
154
155	//___________________________________________
156	ClassImp(AliRICHresponseV0)
157	Float_t AliRICHresponseV0::IntPH(Float_t eloss)
158	{
159	// Get number of electrons and return charge
160
161	Int_t nel;
162	//E9/26=magic number should parameter
163	nel= Int_t(eloss*1.e9/26.);
164	Float_t charge=0;
165	if (nel == 0) nel=1;
166	for (Int_t i=1;i<=nel;i++) {
167	charge -= fChslope*TMath::Log(gRandom->Rndm());
168	}
169	return charge;
170	}
171	// -------------------------------------------
172	Float_t AliRICHresponseV0::IntXY(AliRICHsegmentation * segmentation)
173	{
174
175	const Float_t invpitch = 1/fPitch;
176	Float_t response;
177	//
178	// Integration limits defined by segmentation model
179	//
180
181	Float_t xi1, xi2, yi1, yi2;
182	segmentation->IntegrationLimits(xi1,xi2,yi1,yi2);
183	xi1=xi1*invpitch;
184	xi2=xi2*invpitch;
185	yi1=yi1*invpitch;
186	yi2=yi2*invpitch;
187
188	//
189	// The Mathieson function
190	Double_t ux1=fSqrtKx3TMath::TanH(fKx2xi1);
191	Double_t ux2=fSqrtKx3TMath::TanH(fKx2xi2);
192
193	Double_t uy1=fSqrtKy3TMath::TanH(fKy2yi1);
194	Double_t uy2=fSqrtKy3TMath::TanH(fKy2yi2);
195
196	response=4.fKx4(TMath::ATan(ux2)-TMath::ATan(ux1))fKy4(TMath::ATan(uy2)-TMath::ATan(uy1));
197
198	return response;
199
200	}
201	//___________________________________________
202	Int_t AliRICHresponseV0::FeedBackPhotons(Float_t source[3], Float_t qtot)
203	{
204	//
205	// Generate FeedBack photons
206	//
207	Int_t j, ipart, nt;
208
209	//Probability of feedback
210	Float_t fAlphaFeed=0.05;
211
212	Int_t sNfeed=0;
213
214	// Local variables
215	Float_t cthf, ranf[2], phif, enfp = 0, sthf, weight;
216	Int_t i, ifeed;
217	Float_t e1[3], e2[3], e3[3];
218	Float_t vmod, uswop;
219	Float_t fp, random;
220	Float_t dir[3], phi;
221	Int_t nfp;
222	Float_t pol[3], mom[3];
223	TLorentzVector position;
224	//
225	// Determine number of feedback photons
226
227	// Get weight of current particle
228	TParticle current = (TParticle)
229	(*gAlice->Particles())[gAlice->CurrentTrack()];
230
231	ifeed = Int_t(current->GetWeight()/100+0.5);
232	ipart = gMC->TrackPid();
233	fp = fAlphaFeed * qtot;
234	nfp = gRandom->Poisson(fp);
235
236	// This call to fill the time of flight
237	gMC->TrackPosition(position);
238	//
239	// Generate photons
240	for (i = 0; i <nfp; ++i) {
241
242	// Direction
243	gMC->Rndm(ranf, 2);
244	cthf = ranf[0] * 2 - 1.;
245	if (cthf < 0) continue;
246	sthf = TMath::Sqrt((1 - cthf) * (1 + cthf));
247	phif = ranf[1] * 2 * TMath::Pi();
248	//
249	gMC->Rndm(&random, 1);
250	if (random <= .57) {
251	enfp = 7.5e-9;
252	} else if (random <= .7) {
253	enfp = 6.4e-9;
254	} else {
255	enfp = 7.9e-9;
256	}
257
258	dir[0] = sthf * TMath::Sin(phif);
259	dir[1] = cthf;
260	dir[2] = sthf * TMath::Cos(phif);
261	gMC->Gdtom(dir, mom, 2);
262	mom[0]*=enfp;
263	mom[1]*=enfp;
264	mom[2]*=enfp;
265
266	// Polarisation
267	e1[0] = 0;
268	e1[1] = -dir[2];
269	e1[2] = dir[1];
270
271	e2[0] = -dir[1];
272	e2[1] = dir[0];
273	e2[2] = 0;
274
275	e3[0] = dir[1];
276	e3[1] = 0;
277	e3[2] = -dir[0];
278
279	vmod=0;
280	for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
281	if (!vmod) for(j=0;j<3;j++) {
282	uswop=e1[j];
283	e1[j]=e3[j];
284	e3[j]=uswop;
285	}
286	vmod=0;
287	for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
288	if (!vmod) for(j=0;j<3;j++) {
289	uswop=e2[j];
290	e2[j]=e3[j];
291	e3[j]=uswop;
292	}
293
294	vmod=0;
295	for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
296	vmod=TMath::Sqrt(1/vmod);
297	for(j=0;j<3;j++) e1[j]*=vmod;
298
299	vmod=0;
300	for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
301	vmod=TMath::Sqrt(1/vmod);
302	for(j=0;j<3;j++) e2[j]*=vmod;
303
304	gMC->Rndm(ranf, 1);
305	phi = ranf[0] * 2 * TMath::Pi();
306	for(j=0;j<3;j++) pol[j]=e1[j]TMath::Sin(phi)+e2[j]TMath::Cos(phi);
307	gMC->Gdtom(pol, pol, 2);
308
309	// Put photon on the stack and label it as feedback (51, 52)
310	++sNfeed;
311	if (ipart == 50000050 && ifeed != 50000052) {
312	weight = 5000;
313	} else {
314	weight = 5000;
315	}
316	gAlice->SetTrack(1, gAlice->CurrentTrack(), gMC->PDGFromId(50),
317	mom,source,pol,position[3],
318	"Cherenkov", nt, weight);
319	}
f91473f6	320	return(sNfeed);
ddae0931	321	}