13.25 Highlights of What’s New in Version 28.0.0, 18 June 2015
Here is a summary of what’s changed since release 27.1.0:
13.25.1 Bug Fixes for Elements
- The WATCH element was improved so that the dCt column (in parameter or coordinate
mode) and dt column (in coordinate mode) no longer exhibit fictitious drift due to precision
limitations in simulations of rings with many turns.
- For numerical reasons, any CSBEND with ρ > 106 m is replaced with another element. In the
past, an EDRIFT was used, which would produce incorrect results if the element had non-zero
K1 or K2. This was fixed.
13.25.2 Bug Fixes for Commands
13.25.3 New and Modified Elements
- The TFBPICKUP and TFBDRIVER elements, which provide a turn-by-turn feedback capability,
now support multi-bunch feedback. In addition, support was added for longitudinal feedback
as well as sample/update intervals greater than one turn.
- The CSRDRIFT element can now also include longitudinal space charge, using the algorithm
from the LSCDRIFT element.
- The CSBEND element has a new feature that allows suppression of spurious trajectory offsets
that result from limitations of the symplectic integration routine. This feature is controlled
using the REFERENCE_CORRECTION parameter.
- The input of multipole errors for KQUAD and KSEXT elements was modified so that the input
columns have more transparent names. Previously, the names caused some confusion. Files
that worked with previous versions are still accepted.
- The MARK element with FITPOINT=1 now stores the emittances of the three modes as e1m,
e2m, and e3m for optimization if moments_output is invoked. This deficiency was pointed out
by forum user marlibgin.
13.25.4 New and Modified Commands
- The transmute_elements command now does a better job of copying common parameters
between the old and new element types. In the past, only the length was preserved. A. Zholents
(ANL) reported this issue.
- The floor_coordinates command has a new parameter, store_vertices, which allows
requesting that dipole vertex points be stored for use in optimization.
- The twiss_output command now stores the acceptances Ax and Ay for use in optimization.
13.25.5 Changes for Parallel Version Only
13.25.6 Changes to Related Programs and Files