81 lines
2.1 KiB
Python
81 lines
2.1 KiB
Python
#!/usr/bin/python3
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import spintrum
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import math
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import matplotlib.pyplot as plt
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import numpy as np
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import time
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gammas = [-431.6e4,4257.7e4,4257.7e4,4257.7e4]
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multips = [2,2,2,2]
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jCouplings = \
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[
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[0,-89.3,-89.3,-13.5],
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[0,0,0,8],
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[0,0,0,8],
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[0,0,0,0],
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]
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BThermal = 1.8e0
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T2 = 5
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sampleRate = 2e3
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T= 1/sampleRate
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points = 80000
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specRange = [[0,50],[100,200]]
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gammah = 2*math.pi*4257.7e4
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spinOp = spintrum.SpinOperations()
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spinOp.add_operation(spintrum.SpinOperations.OPERATION__THERMAL_POPULATE,
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{'Bx': 0, 'By': 0, 'Bz': BThermal, 'T': 293.778})
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spinOp.add_operation(spintrum.SpinOperations.OPERATION__TIP_SPINS,
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{'direction': 'y', 'BVsTArea': 4*math.pi/gammah})
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spinOp.add_operation(spintrum.SpinOperations.OPERATION__SET_HAMILTONIAN,
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{'Bx': 0, 'By': 0, 'Bz': 0})
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spinOp.add_operation(spintrum.SpinOperations.OPERATION__INIT_TIME_INDEPENDENT_EVOLUTION,
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{'samplingRate': sampleRate, 'measurementDirection': 'z'})
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spinOp.add_operation(spintrum.SpinOperations.OPERATION__EVOLVE_TIME_INDEPENDENT,
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{'points': points, 'threads': 4})
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def filterSpectrum(spec, freqLim):
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xAxis = np.array([])
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yAxis = np.array([])
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for i in range(len(freqLim)):
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for j in range(len(spec["x"])):
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if spec["x"][j] >= freqLim[i][0] and spec["x"][j] <= freqLim[i][1]:
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xAxis = np.insert(xAxis,-0,spec["x"][j])
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yAxis = np.insert(yAxis,-0,spec["y"][j])
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return {"x": xAxis, "y": yAxis}
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start_time = time.time()
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signal = spintrum.simulate(gyromagneticRatios=gammas,
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jCouplings=jCouplings,
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spinMultiplicities=multips,
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spinOperations=spinOp)
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print("Simulation lastet: " + repr(time.time()-start_time) + "s")
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signal = signal - np.mean(signal)
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signal = [signal[i]*math.exp(-i/sampleRate/T2) for i in range(len(signal))]
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plt.plot(signal)
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plt.show()
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FFT = spintrum.FFTSpectralDensity(signal, sampleRate)
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fft = filterSpectrum(FFT,specRange)
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plt.plot(fft['x'], fft['y'])
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plt.show()
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