This folder contains data sets of x-y image simulations performed
for the LCLS on one screen in the middle of the BC1 chicane at 250
MeV. The chicane bends in the horizontal (x) direction only.

Since the energy is chirped in the chicane in order to compress
the bunch length, the horizontal beam profile in the center of the
chicane is spread out (time correlated) allowing a slice emittance
measurement in the vertical direction by scanning an upstream
quadrupole magnet through various gradient settings. This set of files
is used to simulate the measurement of the vertical slice emittance.

Each image (TIF-file) is from this same BC1 screen, but with an upstream
quadrupole magnet changed for each file (no background-images are provided
since this is a simulation only). The screen has 320 pixels in the
y-direction and 240 pixels in the x-direction. The calibration of the screen is
10 microns/pixel. It is the same for all files in both planes.

The files are:

1). OTRBC11_1.tif,  Q21201: K1 =  -7.4167 m^(-2)
2). OTRBC11_2.tif,  Q21201: K1 =  -8.0525 m^(-2)
3). OTRBC11_3.tif,  Q21201: K1 =  -8.6882 m^(-2)
4). OTRBC11_4.tif,  Q21201: K1 =  -9.3239 m^(-2)
5). OTRBC11_5.tif,  Q21201: K1 =  -9.9596 m^(-2)
6). OTRBC11_6.tif,  Q21201: K1 = -10.5954 m^(-2)
7). OTRBC11_7.tif,  Q21201: K1 = -11.2311 m^(-2)

The quadrupole magnet scanned is named Q21201, has an effective
magnetic length of 0.1068 m, and fits into the beamline layout as
described in the table below (where "dL" is element length, "ang" is bend angle,
K1 is quadrupole strength (as in MAD), E1 is bend entrance angle (as in MAD),
E2 is bend exit angle (as in MAD), hgap is the vertical half-gap in the dipole
(as in MAD). (NOTE: A positive K1-value is focusing for e- in X):

type    dL/m        ang/rad   K1/m^-2       E1/rad      E2/rad      hgap/mm
====================================================================================
QUAD:   0.1068      0         -10.5954      0           0           0       % Q21201
DRIFT:  0.2500      0           0           0           0           0       %
QUAD:   0.1549      0           6.1025      0           0           0       % QM11
DRIFT:  0.3000      0           0           0           0           0       %
BEND:   0.2034      0.084116    0           0           0.084116    13.335  % BX11
DRIFT:  2.6092      0           0           0           0           0       %
BEND:   0.2034     -0.084116    0          -0.084116    0           13.335  % BX12
DRIFT:  0.2500      0           0           0           0           0       %
PROF:   0.0000      0           0           0           0           0       % OTRBC1

The design (nominal) y-twiss parameters on the screen are:
beta_y  = 10.776 m
alpha_y = -1.940

The above beamline detail can be ignored, if preferred, and the transfer matrix from
exit of Q21201-quad to the OTRBC1-screen (PROF) can be used instead.  The transfer matrix
(not including the Q21201 quadrupole) is:

R = [   -2.3795    2.8825       0         0         0           0.2379
        -0.9224    0.6971       0         0         0           0.0000
         0         0            4.3261    4.9556    0           0
         0         0            0.8011    1.1489    0           0
        -0.2195    0.1659       0         0         1.0000      0.0195
         0         0            0         0         0           1.0000]

E-mail to Paul Emma (SLAC) for questions (Emma@SLAC.Stanford.edu).