Validation and Verification of the 15mm collimator simulation, GP2, PhSF

Here we provide code and output which verifies and validates the 15mm collimator simulation. We're using simulation phase space file output and input to check the validity of the result. Geometry of the source is 12mm in length and activity of 120Ci.


In [2]:
import math
import matplotlib
import numpy as np
import matplotlib.pyplot as plt

import BEAMphsf

import beam_loader
import H1Dn
import H1Du
import ListTable

%matplotlib inline

In [3]:
def cm2mm(value):
    """
    converts cm to mm
    """
    return value*10.0

First, set filename to what we want to examine and read PhSF header


In [4]:
C = 15
phsfname = "C" + str(C) + "GP2" + ".egsphsp1"
phsfname = "../" + phsfname
print ("We're reading the {1}mm phase space file = {0}".format(phsfname, C))


We're reading the 15mm phase space file = ../C15GP2.egsphsp1

Checking PhSF header parameters


In [5]:
m, NPPHSP, NPHOTPHSP, EKMAX, EKMIN, NINCP = beam_loader.read_header_byname(phsfname)
print ("We're reading the {1}mm phase space file = {0}".format(phsfname, C))
if m == beam_loader.SHORT:
    print("We have short MODE0 phase space file".format(m))
elif m == beam_loader.LONG:
    print("We have long MODE2 phase space file".format(m))
    
print("Total nof of particle records: {0}".format(NPPHSP))
print("Total nof of photon records: {0}".format(NPHOTPHSP))
print("Maximum kinetic energy: {0} MeV".format(EKMAX))
print("Minimum kinetic energy: {0} MeV".format(EKMIN))
print("Number of original particles: {0}".format(NINCP))
print("Yield: {0}".format(NPHOTPHSP/NINCP))


We're reading the 15mm phase space file = ../C15GP2.egsphsp1
We have long MODE2 phase space file
Total nof of particle records: 5290272
Total nof of photon records: 5290272
Maximum kinetic energy: 1.3300000429153442 MeV
Minimum kinetic energy: 0.010308999568223953 MeV
Number of original particles: 40000000000.0
Yield: 0.0001322568

In [6]:
events, nof_photons, nof_electrons, nof_positrons = beam_loader.load_events(phsfname, -1)

print("Number of loaded events: {0}".format(len(events)))
print("Number of loaded photons: {0}".format(nof_photons))
print("Number of loaded electrons: {0}".format(nof_electrons))
print("Number of loaded positrons: {0}".format(nof_positrons))


Number of loaded events: 5290272
Number of loaded photons: 5290272
Number of loaded electrons: 0
Number of loaded positrons: 0

Convert all spatial coordinates to mm


In [7]:
evts = list()
for event in events:
    wt = event[0]
    e  = event[1]
    x  = cm2mm(event[2])
    y  = cm2mm(event[3])
    zl = cm2mm(event[4])
    wx = event[5]
    wy = event[6]
    wz = event[7]
    
    evts.append(((wt, e, x, y, zl, wx, wy, wz)))
    
events = evts

Energy Spectrum tests

We expect energy spectrum to be scattering background together with peaks δ(E-1.17) and δ(E-1.33). Below we'trying to prove this statement. We will draw the distributions and histograms to estimate influence of the background scattering and get the data about δ-peaks

We're filling energy histogram now, basic checks

We're building scale with 5 bins in the region between 1.17 and 1.33 MeV, all other bins below 1.17 are of about the same size as those 5


In [8]:
# make scale with explicit bins at 1.17 MeV and 1.33 MeV
nbins = 5

scale = BEAMphsf.make_energy_scale(nbins, lo = 0.01, me = 1.1700001, hi = 1.3300001)

he = H1Dn.H1Dn(scale)

for e in events:
    WT = e[0]
    E  = e[1]
    he.fill(E, WT)
    
print("Number of events in histogram: {0}".format(he.nof_events()))
print("Integral in histogram: {0}".format(he.integral()))
print("Underflow bin: {0}".format(he.underflow()))
print("Overflow  bin: {0}".format(he.overflow()))


Number of events in histogram: 5290272
Integral in histogram: 5290272.0
Underflow bin: (0.0, 0, 0.0)
Overflow  bin: (0.0, 0, 0.0)

Underflow bin is close to empty, as well as Overflow bin. This is good because we do not expect events beyond 1.33MeV and below ECUT

Drawing Probability Density Function for 5 bins between 1.33 peak and 1.17 peak.


In [9]:
X = []
Y = []
W = []

scale = he.x()
n     = len(scale)
norm  = 1.0/he.integral()

sum = 0.0

for k in range (-1, he.size()+1):
    x = 0.0
    w = (he.lo() - x)
    if k == he.size():
        w = (scale[-1]-scale[-2])
        x = he.hi()
    elif k >= 0:
        w = (scale[k+1] - scale[k])
        x = scale[k]

    d = he[k]     # data from bin with index k
    y = d[0] / w  # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(w)
    sum += y*w

print("PDF normalization: {0}".format(sum))

E133_5 = Y[-2]
E117_5 = Y[-2-nbins]

p1 = plt.bar(X, Y, W, color='r')

plt.xlabel('Energy(MeV)')
plt.ylabel('PDF of the photons')
plt.title('Energy distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 1.0

In [10]:
# saving peak values
print("Peak PDF value at 1.33 MeV: {0}".format(E133_5))
print("Peak PDF value at 1.17 MeV: {0}".format(E117_5))


Peak PDF value at 1.33 MeV: 13.2528216413069
Peak PDF value at 1.17 MeV: 13.07141556237561

Filling energy histogram with double number of bins

We're building scale with 10 bins in the region between 1.17 and 1.33 MeV, all other bins below 1.17 are of about the same size as those 10


In [11]:
# make scale with explicit bins at 1.17 MeV and 1.33 MeV
nbins = 10

scale = BEAMphsf.make_energy_scale(nbins, lo = 0.01, me = 1.1700001, hi = 1.3300001)

he = H1Dn.H1Dn(scale)

for e in events:
    WT = e[0]
    E  = e[1]
    he.fill(E, WT)
    
print("Number of events in histogram: {0}".format(he.nof_events()))
print("Integral in histogram: {0}".format(he.integral()))
print("Underflow bin: {0}".format(he.underflow()))
print("Overflow  bin: {0}".format(he.overflow()))


Number of events in histogram: 5290272
Integral in histogram: 5290272.0
Underflow bin: (0.0, 0, 0.0)
Overflow  bin: (0.0, 0, 0.0)

Underflow bin is close to empty, as well as Overflow bin. This is good because we do not expect events beyond 1.33MeV and below ECUT

Drawing Probability Density Function for 10 bins between 1.33 peak and 1.17 peak.


In [12]:
X = []
Y = []
W = []

scale = he.x()
n     = len(scale)
norm  = 1.0/he.integral()

sum = 0.0

for k in range (-1, he.size()+1):
    x = 0.0
    w = (he.lo() - x)
    if k == he.size():
        w = (scale[-1]-scale[-2])
        x = he.hi()
    elif k >= 0:
        w = (scale[k+1] - scale[k])
        x = scale[k]

    d = he[k]     # data from bin with index k
    y = d[0] / w  # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(w)
    sum += y*w

print("PDF normalization: {0}".format(sum))

E133_10 = Y[-2]
E117_10 = Y[-2-nbins]

p1 = plt.bar(X, Y, W, color='r')

plt.xlabel('Energy(MeV)')
plt.ylabel('PDF of the photons')
plt.title('Energy distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 1.0

In [13]:
# saving peak values
print("Peak PDF value at 1.33 MeV: {0}".format(E133_10))
print("Peak PDF value at 1.17 MeV: {0}".format(E117_10))


Peak PDF value at 1.33 MeV: 26.287459794127763
Peak PDF value at 1.17 MeV: 25.814705274133328

Filling energy histogram with quadruple number of bins

We're building scale with 20 bins in the region between 1.17 and 1.33 MeV, all other bins below 1.17 are of about the same size as those 20.


In [14]:
# make scale with explicit bins at 1.17 MeV and 1.33 MeV
nbins = 20

scale = BEAMphsf.make_energy_scale(nbins, lo = 0.01, me = 1.1700001, hi = 1.3300001)

he = H1Dn.H1Dn(scale)

for e in events:
    WT = e[0]
    E  = e[1]
    he.fill(E, WT)
    
print("Number of events in histogram: {0}".format(he.nof_events()))
print("Integral in histogram: {0}".format(he.integral()))
print("Underflow bin: {0}".format(he.underflow()))
print("Overflow  bin: {0}".format(he.overflow()))


Number of events in histogram: 5290272
Integral in histogram: 5290272.0
Underflow bin: (0.0, 0, 0.0)
Overflow  bin: (0.0, 0, 0.0)

Underflow bin is close to empty, as well as Overflow bin. This is good because we do not expect events beyond 1.33MeV and below ECUT

Drawing Probability Density Function for 10 bins between 1.33 peak and 1.17 peak.


In [15]:
X = []
Y = []
W = []

scale = he.x()
n     = len(scale)
norm  = 1.0/he.integral()

sum = 0.0

for k in range (-1, he.size()+1):
    x = 0.0
    w = (he.lo() - x)
    if k == he.size():
        w = (scale[-1]-scale[-2])
        x = he.hi()
    elif k >= 0:
        w = (scale[k+1] - scale[k])
        x = scale[k]

    d = he[k]     # data from bin with index k
    y = d[0] / w  # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(w)
    sum += y*w

print("PDF normalization: {0}".format(sum))

E133_20 = Y[-2]
E117_20 = Y[-2-nbins]

p1 = plt.bar(X, Y, W, color='r')

plt.xlabel('Energy(MeV)')
plt.ylabel('PDF of the photons')
plt.title('Energy distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.9999999999999998

In [16]:
# saving peak values
print("Peak PDF value at 1.33 MeV: {0}".format(E133_20))
print("Peak PDF value at 1.17 MeV: {0}".format(E117_20))


Peak PDF value at 1.33 MeV: 52.32609022749676
Peak PDF value at 1.17 MeV: 51.237063047041765

Comparing peak values

We would compare peak values at 10 bins and at 5 bins. The presence of δ-peaks means that with doubling number of bins we shall expect the roughly doubling the peak values.


In [17]:
table = ListTable.ListTable()

table.append(["Nbins", "E=1.17", "E=1.33"])
table.append(["", "MeV", "MeV"])
table.append([5, 1.0, 1.0])
table.append([10, E133_10/E133_5, E133_10/E133_5])
table.append([20, E133_20/E133_5, E133_20/E133_5])
table


Out[17]:
NbinsE=1.17E=1.33
MeVMeV
51.01.0
101.98353682752312951.9835368275231295
203.9482980789845393.948298078984539

The result is as expected. Only few percent of the values in the 1.33 and 1.17 MeV bins are due to scattered radiation. Most values are coming from primary source and are δ-peaks in energy.

Spatial Distribution tests

Here we will plot spatial distribution of the particles, projected from collimator exit position to the isocenter location at 38cm


In [18]:
Znow  = 200.0 # we at 000mm at the cooolimator exit
Zshot = 360.0 # shot isocenter is at 380mm

# radial, X and Y, all units in mm
hr = H1Du.H1Du(120, 0.0, 40.0)
hx = H1Du.H1Du(128, -32.0, 32.0)
hy = H1Du.H1Du(128, -32.0, 32.0)

for e in events:
    WT = e[0]
    xx, yy, zz = BEAMphsf.move_event(e, Znow, Zshot)
    
    #xx = e[2]
    #yy = e[3]
    #zz = e[4]
    
    r = math.sqrt(xx*xx + yy*yy)
    hr.fill(r, WT)
    hx.fill(xx, WT)
    hy.fill(yy, WT)

print("Number of events in R histogram: {0}".format(hr.nof_events()))
print("Integral in R histogram: {0}".format(hr.integral()))
print("Underflow bin: {0}".format(hr.underflow()))
print("Overflow  bin: {0}\n".format(hr.overflow()))

print("Number of events in X histogram: {0}".format(hx.nof_events()))
print("Integral in X histogram: {0}".format(hx.integral()))
print("Underflow bin: {0}".format(hx.underflow()))
print("Overflow  bin: {0}\n".format(hx.overflow()))

print("Number of events in Y histogram: {0}".format(hy.nof_events()))
print("Integral in Y histogram: {0}".format(hy.integral()))
print("Underflow bin: {0}".format(hy.underflow()))
print("Overflow  bin: {0}".format(hy.overflow()))


Number of events in R histogram: 5290272
Integral in R histogram: 5290272.0
Underflow bin: (0.0, 0, 0.0)
Overflow  bin: (145525.0, 145525, 145525.0)

Number of events in X histogram: 5290272
Integral in X histogram: 5290272.0
Underflow bin: (55996.0, 55996, 55996.0)
Overflow  bin: (56001.0, 56001, 56001.0)

Number of events in Y histogram: 5290272
Integral in Y histogram: 5290272.0
Underflow bin: (55922.0, 55922, 55922.0)
Overflow  bin: (55889.0, 55889, 55889.0)

In [19]:
X = []
Y = []
W = []

norm  = 1.0/hr.integral()

sum = 0.0

st = hr.step()

for k in range (0, hr.size()+1):
    r_lo = hr.lo() + float(k) * st
    r_hi = r_lo + st
    r = 0.5*(r_lo + r_hi)
    
    ba = math.pi * (r_hi*r_hi - r_lo*r_lo) # bin area

    d = hr[k]      # data from bin with index k
    y = d[0] / ba  # first part of bin is collected weights
    y = y * norm
    X.append(r)
    Y.append(y)
    W.append(st)
    sum += y * ba

print("PDF normalization: {0}".format(sum))

p1 = plt.bar(X, Y, W, 0.0, color='b')

plt.xlabel('Radius(mm)')
plt.ylabel('PDF of the photons')
plt.title('Radial distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.9999999999999997

NB: peak at the far right above 40mm is overflow bin


In [20]:
X = []
Y = []
W = []

norm  = 1.0/hx.integral()

sum = 0.0

st = hx.step()    

for k in range (0, hx.size()):
    x_lo = hx.lo() + float(k)*st
    x_hi = x_lo + st
    x    = 0.5*(x_lo + x_hi)

    d = hx[k]        # data from bin with index k
    y = d[0] / st    # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(st)
    sum += y*st

print("PDF normalization: {0}".format(sum))

p1 = plt.bar(X, Y, W, color='b')

plt.xlabel('X(mm)')
plt.ylabel('PDF of the photons')
plt.title('X distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.9788296329564907

In [21]:
X = []
Y = []
W = []

norm  = 1.0/hy.integral()

sum = 0.0

st = hy.step()

for k in range (0, hy.size()):
    x_lo = hy.lo() + float(k)*st
    x_hi = x_lo + st
    x    = 0.5*(x_lo + x_hi)

    d = hy[k]       # data from bin with index k
    y = d[0] / st    # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(st)
    sum += y*st

print("PDF normalization: {0}".format(sum))

p1 = plt.bar(X, Y, W, color='b')

plt.xlabel('Y(mm)')
plt.ylabel('PDF of the photons')
plt.title('Y distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.978864791829229

We find spatial distribution to be consistent with the collimation setup

Angular Distribution tests

Here we plot particles angular distribution for all three directional cosines, at the collimator exit. We expect angular distribution to fill collimation angle which is close to 0.017 radians (0.5x15/380).


In [22]:
# angular, WZ, WX and WY, all units in radians
h_wz = H1Du.H1Du(100, 1.0 - 0.05, 1.0)
h_wx = H1Du.H1Du(110, -0.055, 0.055)
h_wy = H1Du.H1Du(110, -0.055, 0.055)

for e in events:
    WT = e[0]
    
    wx = e[5]
    wy = e[6]
    wz = e[7]
    
    h_wz.fill(wz, WT)
    h_wx.fill(wx, WT)
    h_wy.fill(wy, WT)

print("Number of events in WZ histogram: {0}".format(h_wz.nof_events()))
print("Integral in WZ histogram: {0}".format(h_wz.integral()))
print("Underflow bin: {0}".format(h_wz.underflow()))
print("Overflow  bin: {0}\n".format(h_wz.overflow()))

print("Number of events in WX histogram: {0}".format(h_wx.nof_events()))
print("Integral in WX histogram: {0}".format(h_wx.integral()))
print("Underflow bin: {0}".format(h_wx.underflow()))
print("Overflow  bin: {0}\n".format(h_wx.overflow()))

print("Number of events in WY histogram: {0}".format(h_wy.nof_events()))
print("Integral in WY histogram: {0}".format(h_wy.integral()))
print("Underflow bin: {0}".format(h_wy.underflow()))
print("Overflow  bin: {0}".format(h_wy.overflow()))


Number of events in WZ histogram: 5290272
Integral in WZ histogram: 5290272.0
Underflow bin: (111983.0, 111983, 111983.0)
Overflow  bin: (0.0, 0, 0.0)

Number of events in WX histogram: 5290272
Integral in WX histogram: 5290272.0
Underflow bin: (85824.0, 85824, 85824.0)
Overflow  bin: (85936.0, 85936, 85936.0)

Number of events in WY histogram: 5290272
Integral in WY histogram: 5290272.0
Underflow bin: (86067.0, 86067, 86067.0)
Overflow  bin: (86163.0, 86163, 86163.0)

In [23]:
X = []
Y = []
W = []

norm  = 1.0/h_wz.integral()

sum = 0.0

st = h_wz.step()

for k in range (0, h_wz.size()+1):
    x_lo = h_wz.lo() + float(k)*st
    x_hi = x_lo + st
    x    = 0.5*(x_lo + x_hi)

    d = h_wz[k]       # data from bin with index k
    y = d[0] / st     # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(st)
    sum += y*st

print("PDF normalization: {0}".format(sum))

p1 = plt.bar(X, Y, W, color='g')

plt.xlabel('WZ')
plt.ylabel('PDF of the photons')
plt.title('Angular Z distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.9788322793232558

In [24]:
X = []
Y = []
W = []

norm  = 1.0/h_wx.integral()

sum = 0.0

st = h_wx.step()

for k in range (0, h_wx.size()):
    x_lo = h_wx.lo() + float(k)*st
    x_hi = x_lo + st
    x    = 0.5*(x_lo + x_hi)

    d = h_wx[k]       # data from bin with index k
    y = d[0] / st     # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(st)
    sum += y*st

print("PDF normalization: {0}".format(sum))

p1 = plt.bar(X, Y, W, color='g')

plt.xlabel('WX')
plt.ylabel('PDF of the photons')
plt.title('Angular X distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.9675328603141771

In [25]:
X = []
Y = []
W = []

norm  = 1.0/h_wy.integral()

sum = 0.0

st = h_wy.step()

for k in range (0, h_wy.size()):
    x_lo = h_wy.lo() + float(k)*st
    x_hi = x_lo + st
    x    = 0.5*(x_lo + x_hi)

    d = h_wy[k]       # data from bin with index k
    y = d[0] / st     # first part of bin is collected weights
    y = y * norm
    X.append(x)
    Y.append(y)
    W.append(st)
    sum += y*st

print("PDF normalization: {0}".format(sum))

p1 = plt.bar(X, Y, W, color='g')

plt.xlabel('WY')
plt.ylabel('PDF of the photons')
plt.title('Angular Y distribution')

plt.grid(True);
plt.tick_params(axis='x', direction='out')
plt.tick_params(axis='y', direction='out')

plt.show()


PDF normalization: 0.9674440180013428

We find photon angular distribution to be consistent with the collimation setup

Conclusion

After plotting and analyzing photons energy, spatial and angular distribution, we could conclude that it is consistent with simulation Co60 source, sending particles through collimation system of 15mm collimation spot at 360mm isocenter.