Content

Image processing in cxif5315

The best options for image processing in cxif5315

• Water background is evaluated WITH COMMON MODE CORRECTION that enhance intensity of central 2x1... - needs to be re-calibrated

• DO NOT use common mode

• polarization factor map should be rotated by 90 degree because of requested by Meng fancy 90 degree rotation in the geometry file
• USE status mask
• USE radial background subtraction for single angular bin

        Xarr =  sp.det.coords_x(runnum)
        Yarr =  sp.det.coords_y(runnum)

        sp.rb = RadialBkgd(Xarr, Yarr, mask=sp.nda_smask, radedges=(5200, 80000), nradbins=200, nphibins=1)
        sp.pf = polarization_factor(sp.rb.pixel_rad(), sp.rb.pixel_phi()+90, sp.DETD_um)

    nda_raw = sp.det.raw(evt)

    if nda_raw is not None :

        nda =  np.array(nda_raw, dtype=np.float32, copy=True)
        nda -= sp.nda_peds
        #nda =  subtract_bkgd(nda, sp.nda_bkgd, mask=sp.nda_smask, winds=sp.winds_bkgd, pbits=0)

        nda = sp.rb.subtract_bkgd(nda.flatten() * sp.pf)
        nda.shape = sp.nda_peds.shape

        nda *= sp.nda_smask
        #sp.det.common_mode_apply(evt, nda)
        
        img = getImage(evt, nda)

Fit results

Averaged Fraser- transformed image using angles from fit to 2 arc peaks

Distance between 2 peaks in Arc region

Radius of the median point of 2 peaks in Arc region

Fit results for for phi and beta in ARC region

Negative solution y = -B - sqrt(B*B-C)

y = funcy_l1(x, phi_deg, bet_deg, DoR=390/913.27, sgnrt=-1.)

Positive solution y = -B + sqrt(B*B-C)

y = funcy_l1(x, phi_deg, bet_deg, DoR=390/913.27, sgnrt=+1.)

Fit results for peak list from Meng

Equatorial region

Arc region (positive root)

Arc region (negative root)