Tapering does not restore tunes

[bogomyag]

Tapering does not restore tunes in PTC_TWISS and in TWISS.

I understand from manual (chapter 38) that TWISS calculates optic functions in 4d only, therefore it is expected that with RF cavities and RADIATION=ON only the X,Y,PT will be approximately correct, but the tunes will not. However, PTC_TWISS should correctly calculate the orbit and optical functions, which is not the case as demonstrated in run-test-1.madx

twiss (radiation off) @ Q1 %le 220.544999999977 @ Q2 %le 219.60999999979

twiss (radiation on) @ Q1 %le 220.546533628453 @ Q2 %le 219.612476383926

ptc-twiss (radiation on) @ Q1 %le 0.546583283413037 @ Q2 %le 0.612737897188153

twiss tunes (radiation on, tapering on) @ Q1 %le 220.56335366833 @ Q2 %le 219.621529278762

ptc-twiss (radiation on, tapering on) @ Q1 %le 0.676054382201816 @ Q2 %le 0.5

I use +++++++++++++++++++++++++++++++++++++++ test-1.zip +++++

• MAD-X 5.09.01  (64 bit, Windows)                                              +
  

• Support: [email protected], http://cern.ch/mad +
• Release date: 2023.12.04 +
• Execution date: 2024.05.06 10:51:32 + ++++++++++++++++++++++++++++++++++++++++++++