24-Sep-2004
Richard:
The following is the result of a quick scan through the optics of Yang's 
2-magnet tagger, producing tables like Table 4.6 of Version 4.

THE RESULTS FOR k(=Egamma) BELOW 7 GeV ARE ONLY A ROUGH ESTIMATE,
since the calculation assumes a single continuous magnet. 
(I have not yet set up the 2-magnet transition in my code.)
However, my radial focal positions are not far off from Yang's linear 
focal plane, so the estimate may not be a very bad one.

I have reduced the quadrupole field slightly in order to give maximum
"dytot" (due to beam size and angle) at Egam = 9 GeV.
Compared to the old optics, dytot varies much more strongly with photon
energy -- this is probably because the rectangular magnet design gives
additional vertical defocusing which interferes with the effect of the
quadrupole in a mometnum-dependent way.  We could fix this by playing
with the dipole edge. I don't think Yang and Jim K. understood what we
are aiming for in this respect.

Hope this is useful.
Dan



 ========================================================================
 SET 1:  Fixed linear focal plane, No quad.

 Transport matrix elements from file tag2mag3.OU2                  Set  1
 Resolution in GeV for E0 =  12.000

 Definitions:  (resolution in units of GeV )
     dk_spot= resol. due to spot size
     dk_foc = resol. due to non-focus, using  char. angle and beam angle
     dk_lim = limiting resolution (beam+spot+focus)
     dk(0.1)= resol. including counter width of .1%
     dk(0.2)= resol. including counter width of .2%
     dy(y)  = transverse resol. due to beam size
     dy(y') = transverse resol. due to beam angle
     dytot  = transverse resol. combined
     dy_char = transv. size of 1 electron char. angle


 Beam resolution values (1 sigma):
                  Radial  Transverse
  Size  (mm)     1.7000      0.5000
  Angle (mr)     0.0200      0.0050
  dp0/p0 (%)     0.0800

 Resolutions (dk in GeV, dy in mm):
 k(GeV) dkspot dk_foc dk_lim dk(.1) dk(.2)     dy(y) dy(y')  dytot dychar
         (GeV)  (GeV)  (GeV)  (GeV)  (GeV)      (mm)   (mm)   (mm)   (mm)
 11.000 0.0008 0.0001 0.0096 0.0102 0.0119    1.0015 0.0481 1.0027 4.5100
 10.000 0.0019 0.0001 0.0098 0.0104 0.0120    1.1095 0.0638 1.1113 2.7170
  9.000 0.0032 0.0000 0.0101 0.0107 0.0123    1.1860 0.0781 1.1886 1.9960
  8.000 0.0048 0.0001 0.0107 0.0113 0.0128    1.2480 0.0921 1.2514 1.5680
  7.000 0.0064 0.0001 0.0116 0.0121 0.0135    1.3015 0.1059 1.3058 1.2620
  6.000 0.0081 0.0002 0.0126 0.0130 0.0143    1.3490 0.1197 1.3543 1.0190
  5.000 0.0098 0.0002 0.0137 0.0141 0.0153    1.3920 0.1335 1.3984 0.8120
  4.000 0.0114 0.0003 0.0149 0.0153 0.0165    1.4305 0.1475 1.4381 0.6280
  3.000 0.0131 0.0003 0.0162 0.0166 0.0176    1.4665 0.1616 1.4754 0.4590

 ========================================================================
 SET 3:  Fixed linear focal plane, Quad strength = -0.40

 Transport matrix elements from file tag2mag3.OU2                  Set  3
 Resolution in GeV for E0 =  12.000

 Definitions:  (resolution in units of GeV )
     dk_spot= resol. due to spot size
     dk_foc = resol. due to non-focus, using  char. angle and beam angle
     dk_lim = limiting resolution (beam+spot+focus)
     dk(0.1)= resol. including counter width of .1%
     dk(0.2)= resol. including counter width of .2%
     dy(y)  = transverse resol. due to beam size
     dy(y') = transverse resol. due to beam angle
     dytot  = transverse resol. combined
     dy_char = transv. size of 1 electron char. angle


 Beam resolution values (1 sigma):
                  Radial  Transverse
  Size  (mm)     1.7000      0.5000
  Angle (mr)     0.0200      0.0050
  dp0/p0 (%)     0.0800

 Resolutions (dk in GeV, dy in mm):
 k(GeV) dkspot dk_foc dk_lim dk(.1) dk(.2)     dy(y) dy(y')  dytot dychar
         (GeV)  (GeV)  (GeV)  (GeV)  (GeV)      (mm)   (mm)   (mm)   (mm)
 11.000 0.0003 0.0006 0.0096 0.0102 0.0119   -0.8900 0.0198 0.8902 1.8530
 10.000 0.0007 0.0004 0.0096 0.0102 0.0119   -0.2705 0.0431 0.2739 1.8370
  9.000 0.0022 0.0002 0.0098 0.0104 0.0120   -0.0005 0.0604 0.0604 1.5420
  8.000 0.0039 0.0000 0.0104 0.0109 0.0125    0.1625 0.0758 0.1793 1.2910
  7.000 0.0057 0.0001 0.0112 0.0117 0.0131    0.2765 0.0905 0.2909 1.0790
  6.000 0.0075 0.0002 0.0122 0.0127 0.0140    0.3635 0.1049 0.3783 0.8930
  5.000 0.0094 0.0002 0.0134 0.0139 0.0151    0.4335 0.1192 0.4496 0.7250
  4.000 0.0112 0.0002 0.0148 0.0152 0.0163    0.4920 0.1334 0.5098 0.5680
  3.000 0.0131 0.0003 0.0162 0.0166 0.0176    0.5420 0.1477 0.5618 0.4190