In [1]:
%pylab inline
from scipy.interpolate import interp1d

from IPython.display import Image


Populating the interactive namespace from numpy and matplotlib

Details

Below are the recorded measurements for the first batch of cutout factor measurements

Ionisation conversion

The following cell is used to initialise the ionisation to dose conversion function. Data is extracted from table 20 within TRS398. R50 of the 12 MeV beam is $4.75~g/cm^2$


In [2]:
zOnR50 = concatenate((array([0.02]), arange(0.05,1.25,0.05)))
R50of45 = array([0.997,1,1.004,1.008,1.012,1.017,1.021,1.026,1.03,
                 1.035,1.04,1.045,1.051,1.056,1.062,1.067,1.073,1.08,
                 1.086,1.092,1.099,1.106,1.113,1.120,1.128])

R50of50 = array([0.991,0.994,0.998,1.002,1.006,1.011,1.016,1.02,1.025,
                 1.03,1.035,1.041,1.046,1.052,1.058,1.064,1.07,1.076,
                 1.083,1.09,1.097,1.104,1.112,1.119,1.128])

R50of47_5 = mean([R50of45,R50of50],axis=0)

stopRatio = interp1d(zOnR50 * 47.5,R50of47_5)

Measurements

These measurements were done on Harry 2694, with a Markus chamber set to +300 V. The sensitivity was $1.398 \times 10^9$. All measurements were done at 100 SSD with a 12 MeV beam and a $10\times10$ cm applicator. Below are the readings recorded in chronological order.

Readings


In [3]:
standard_insert_reading = {}
cutout_reading = {}
factor = {}

Standard Insert


In [4]:
standard_insert_reading = array([])

standard_insert_reading = append(standard_insert_reading,mean([1.533,1.533,1.533])) # Measured before
standard_insert_reading = append(standard_insert_reading,mean([1.532,1.531,1.532])) # Measured after

standard_insert_reading = mean(standard_insert_reading)

Output function definition


In [5]:
def outputFunction(cutout,depth,readings):
    
    if size(readings) == 1:
        
        cutout_reading = readings
        
    else:
    
        stop_ratio_corrected = stopRatio(depth) * readings

        scatter(depth,stop_ratio_corrected)
        ylabel('Stopping power ratio corrected')
        xlabel('Depth (mm)')
        title('Relative ionsation to relative dose')
        show()

        cutout_reading = readings[argmax(stop_ratio_corrected)]
    
    
    print("Reading = %0.3f" %(cutout_reading))

    factor = standard_insert_reading / cutout_reading
    print("Cutout factor = %0.3f | %0.1f%%" %(factor, (factor - 1) * 100))
   
    return cutout_reading, factor

Cutout readings


In [6]:
cutout = '043'
cutout_reading[cutout] = mean([1.521,1.520]) # ionisation at depth 25 mm RW3
# cutout_reading[cutout] = mean([1.445,]) # ionisation at depth 24 mm RW3

factor[cutout] = standard_insert_reading / cutout_reading[cutout]
print("Cutout factor = %0.3f | %0.1f%%" %(factor[cutout], (factor[cutout] - 1) * 100))

Image('../figures/saved/'+cutout+'.png')


Cutout factor = 1.008 | 0.8%
Out[6]:

In [7]:
cutout = '106'
cutout_reading[cutout] = mean([1.531,1.531,1.531]) # ionisation at depth 25 mm RW3

factor[cutout] = standard_insert_reading / cutout_reading[cutout]
print("Cutout factor = %0.3f | %0.1f%%" %(factor[cutout], (factor[cutout] - 1) * 100))

Image('../figures/saved/'+cutout+'.png')


Cutout factor = 1.001 | 0.1%
Out[7]:

In [8]:
cutout = '058'
cutout_reading[cutout] = mean([1.518,1.519,1.519]) # ionisation at depth 25 mm RW3

factor[cutout] = standard_insert_reading / cutout_reading[cutout]
print("Cutout factor = %0.3f | %0.1f%%" %(factor[cutout], (factor[cutout] - 1) * 100))

Image('../figures/saved/'+cutout+'.png')


Cutout factor = 1.009 | 0.9%
Out[8]:

In [9]:
cutout = '033'
cutout_reading[cutout] = mean([1.522,1.522,1.522]) # ionisation at depth 25 mm RW3

factor[cutout] = standard_insert_reading / cutout_reading[cutout]
print("Cutout factor = %0.3f | %0.1f%%" %(factor[cutout], (factor[cutout] - 1) * 100))

Image('../figures/saved/'+cutout+'.png')


Cutout factor = 1.007 | 0.7%
Out[9]:

In [10]:
cutout = '019'
cutout_reading[cutout] = mean([1.530,1.531,1.531]) # ionisation at depth 25 mm RW3

factor[cutout] = standard_insert_reading / cutout_reading[cutout]
print("Cutout factor = %0.3f | %0.1f%%" %(factor[cutout], (factor[cutout] - 1) * 100))

Image('../figures/saved/'+cutout+'.png')


Cutout factor = 1.001 | 0.1%
Out[10]:

In [11]:
cutout = '083'

depth = array([25,24,23,22])
readings = array([])

readings = append(readings,mean([1.516,1.517,1.516])) # ionisation at depth 25 mm RW3
readings = append(readings,mean([1.519,1.519])) # ionisation at depth 24 mm RW3
readings = append(readings,mean([1.522])) # ionisation at depth 23 mm RW3
readings = append(readings,mean([1.520])) # ionisation at depth 22 mm RW3

cutout_reading[cutout], factor[cutout] = outputFunction(cutout,depth,readings)

Image('../figures/saved/'+cutout+'.png')


Reading = 1.516
Cutout factor = 1.011 | 1.1%
Out[11]:

In [12]:
with open('cutout_factors','r') as f:
    
    loaded_factors = eval(f.read())

    
factors_to_save = dict(list(loaded_factors.items()) + list(factor.items()))

with open('cutout_factors','w') as f:
    
    f.write(str(factors_to_save))