SIS18_TH_HTC_STANDARD optics

(return)

The length of this path, from SIS18 extraction point (PSE) to HTC target is 195.37 meters.

Optics files obtained from MADX on April 8, 2018:

Remarks:

1. Accelerator zones do not take into account new division on GHTCDIAE.

The betas along the beamline:

older investigations:

Direct optics from SIS-18. The twiss file SC__.twiss:

MADX beta functions:

Preliminary optics functions on target:

Assuming 1-sigma emittances (for slow extraction) as explained here:

eH=0.25 mm*mrad, eV=1*mm*mrad,

the expected beam sizes on target are:

sigma_H = 3.1 mm, sigma_V=8.7 mm

After matching of the final triplet for better final focus one gets significant better horizontal and vertical beta functions of, respectively, 11.7 and 5.9 meters:

MATCH SUMMARY

Node_Name              Constraint   Type  Target Value   Final Value      Penalty
---------------------------------------------------------------------------------------
sis18_th_htc$end:1     betx         4     0.0000E+00     1.176475E+01     1.38409E+02
sis18_th_htc$end:1     bety         4     0.0000E+00     5.876509E+00     3.45334E+01

Final Penalty Function =   1.72942586e+02

Variable                 Final Value  Initial Value Lower Limit  Upper Limit 
--------------------------------------------------------------------------------
k1_ghtcqt21              -4.41821e-02  1.91185e-01  0.00000e+00  6.00000e-01
k1_ghtcqt22              -5.67390e-02 -3.68248e-01 -6.00000e-01  0.00000e+00
k1_ghtcqt23               1.47148e-01  2.48794e-01  0.00000e+00  6.00000e-01

A look on the optics used in June 2016 shows significant differences with respect to theoretical optics, and very large beta functions on target. This is further investigated.