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eos/libeos/instrument.py

120 lines
4.7 KiB
Python

"""
Classes describing the AMOR instrument configuration used during reduction.
"""
import logging
from functools import cache
import numpy as np
from . import const
class Detector:
nBlades = 14 # number of active blades in the detector
nWires = 32 # number of wires per blade
nStripes = 64 # number of stipes per blade
angle = np.deg2rad(5.1) # deg angle of incidence of the beam on the blades (def: 5.1)
dZ = 4.0*np.sin(angle) # mm height-distance of neighboring pixels on one blade
dX = 4.0*np.cos(angle) # mm depth-distance of neighboring pixels on one blace
bladeZ = 10.455 # mm distance between detector blades
zero = 0.5*nBlades*bladeZ # mm vertical center of the detector
distance = 4000. # mm distance from focal point to leading blade edge
delta_z: np.ndarray
pixelLookUp: np.ndarray
@staticmethod
def resolve_pixels():
"""
Determine spatial coordinats and angles from pixel number,
does only have to be computed once for the detector
"""
if hasattr(Detector, 'pixelLookUp'):
return
nPixel = Detector.nWires * Detector.nStripes * Detector.nBlades
pixelID = np.arange(nPixel)
(bladeNr, bPixel) = np.divmod(pixelID, Detector.nWires * Detector.nStripes)
(bZi, detYi) = np.divmod(bPixel, Detector.nStripes) # z index on blade, y index on detector
detZi = bladeNr * Detector.nWires + bZi # z index on detector
detX = bZi * Detector.dX # x position in detector
# detZ = Detector.zero - bladeNr * Detector.bladeZ - bZi * Detector.dZ # z position on detector
bladeAngle = np.rad2deg( 2. * np.arcsin(0.5*Detector.bladeZ / Detector.distance) )
delta = (Detector.nBlades/2. - bladeNr) * bladeAngle \
- np.rad2deg( np.arctan(bZi*Detector.dZ / ( Detector.distance + bZi * Detector.dX) ) )
delta_z = delta[detYi==1]
pixel_lookup=np.vstack((detYi.T, detZi.T, detX.T, delta.T)).T
Detector.delta_z = delta_z
Detector.pixelLookUp = pixel_lookup
# guarantee that pixelLookUp has been computed
Detector.resolve_pixels()
class LZGrid:
dldl = 0.005 # Delta lambda / lambda
# as using cahced results, make sure the object is not modified
@property
def qResolution(self):
return self._qResolution
@property
def qzRange(self):
return self._qzRange
def __init__(self, qResolution, qzRange):
self._qResolution = qResolution
self._qzRange = qzRange
@property
@cache
def shape(self):
# gives the shape of the grid, not of the bin-edges
return (self.lamda().shape[0]-1, self.z().shape[0]-1)
@cache
def q(self):
resolutions = [0.005, 0.01, 0.02, 0.025, 0.04, 0.05, 0.1, 1]
a, b = np.histogram([self.qResolution], bins = resolutions)
dqdq = np.matmul(b[:-1],a)
if dqdq != self.qResolution:
logging.info(f'# changed resolution to {dqdq}')
qq = 0.01
# linear up to qq
q_grid = np.arange(0, qq, qq*dqdq)
# exponential from qq on
q_grid = np.append(q_grid, qq*(1.+dqdq)**np.arange(int(np.log(self.qzRange[1]/qq)/np.log(1+dqdq))))
q_grid = q_grid[q_grid>=self.qzRange[0]]
return q_grid
@cache
def lamda(self):
lamdaMax = 16
lamdaMin = const.lamdaCut
lamda_grid = lamdaMin*(1+self.dldl)**np.arange(int(np.log(lamdaMax/lamdaMin)/np.log(1+self.dldl)+1))
return lamda_grid
@cache
def z(self):
return np.arange(Detector.nBlades*Detector.nWires+1)
@cache
def lz(self):
return np.ones(( self.lamda().shape[0]-1, self.z().shape[0]-1))
@cache
def delta(self, detectorDistance):
# unused for now
bladeAngle = np.rad2deg( 2. * np.arcsin(0.5*Detector.bladeZ / detectorDistance) )
blade_grid = np.arctan( np.arange(33) * Detector.dZ / ( detectorDistance + np.arange(33) * Detector.dX) )
blade_grid = np.rad2deg(blade_grid)
stepWidth = blade_grid[1] - blade_grid[0]
blade_grid = blade_grid - 0.2 * stepWidth
delta_grid = []
for b in np.arange(Detector.nBlades-1):
delta_grid = np.concatenate((delta_grid, blade_grid), axis=None)
blade_grid = blade_grid + bladeAngle
delta_grid = delta_grid[delta_grid<blade_grid[0]-0.5*stepWidth]
delta_grid = np.concatenate((delta_grid, blade_grid), axis=None)
return -np.flip(delta_grid) + 0.5*Detector.nBlades * bladeAngle