The OPAL Discussion Forum

["Dr. Simon Friederich" <s.friederich AT uni-mainz.de>]

Dear Philippe,

Could it be, that you are shooting your beam against the side of your cavity as it is rotated around the X-axis?

> ORIENTATION = {-Pi/2.,0.0, 0.0}
      If so, you loose your beam, since it flies against the fringe of
      your fieldmap (and not your entry).

Best regards
Simon

Dr. Simon Friederich
Helmholtz-Institut Mainz | Insitut für Kernphysik
Kollaboration ACID       | B
Johannes Gutenberg-Universität Mainz
Staudingerweg 18         | Johann-Joachim-Becherweg 45
55128 Mainz, Deutschland

Tel.: +49 (0)6131 39-23160
E-Mail: s.friederich AT uni-mainz.de

Am 14.09.2021 um 12:57 schrieb Philippe Piot:

Dear All,

  I have a very simple beamline as follows:

TDC:   RFCavity, L = 0.032, VOLT = 1*Vtdc, ORIGIN = {0,0,0.016},
       ORIENTATION = {-Pi/2.,0.0, 0.0}, TYPE = "STANDING",
       FMAPFN = "./xBandDeflector.T7", FREQ = 11700.0, LAG = tdcPhi;
DR1: DRIFT, L = 1.0, ORIGIN = {0., 0., 0.0};
MyLine: Line = (TDC, DR1);

combined with the track command

TRACK, LINE = MyLine, BEAM = BEAM1, MAXSTEPS = 1900000, DT = 1.0e-13, ZSTOP=0.15;

  Somehow OPAL always end at 0.032 (which appears to coincide with the end of the RFCavity element) and the output ends with

OPAL {0}[2]> * Wrote beam phase space.
ParallelTTracker {0}[2]> Dump phase space of last step
Ippl{0}[3]> DR1 gone off
Ippl{0}[3]> DR2 gone off
Ippl{0}[3]>
Ippl{0}[3]> * ************ I N F O *********************************************************
Ippl{0}[3]> * freed fieldmap './xBandDeflector.T7'                                         *
Ippl{0}[3]> * ******************************************************************************
Ippl{0}[3]>
Ippl{0}[3]>
Ippl{0}[3]> TDC gone off
OPAL{0}> done executing ParallelTTracker at 05:54:44
OPAL{0}> * End of input stream "deflector.in".

  Somehow it claims (I think the "gone off" meaning) there is no more element after the RFCavity?

    I also tried different combinations with drift but it did not help. Thank you, -- Philippe.