13.8 Highlights of What’s New in Version 2021.3

Here is a summary of what’s changed since release 2021.2.

13.8.1 Bug Fixes for Elements

• The voltage setpoint adjustment feature of RFMODE will now work in the serial version.
• There was a bug in the I/Q feedback for RFMODE that essentially added the beamloading voltage to the setpoint. This was pointed out by Z. Duan (IHEP), who also provided a correction to the code.

13.8.2 Bug Fixes for Commands

• Fixed a lattice lattice parser bug that would cause a crash when a single reflected element appeared with a quoted name.
• A bug was fixed in the ramp_elements and modulate_elements commands that would cause incorrect values to be asserted when multiple elements of the same name were targetted in the default differential mode.
• The chromaticity command was ignoring the update_orbit parameter and not fully updating the twiss parameters as the correction was performed. In cases with large orbits and strong sextupoles, this would cause a discrepancy between the claimed corrected chromaticity and the actual chromaticity (as reported by the twiss_output command). This was reported by V. Sajaev (ANL).

13.8.3 New and Modified Elements

• Thanks to A. J. Dick and P. Piot (NIU), two new elements were added that allow simulation of Optical Stochastic Cooling. The CPICKUP element is used to record information from the pickup undulator, while the CKICKER element is used to impart corresponding kicks to the beam. See the manual pages for more detail.
• The RFMODE element now checks that the A0 coefficient is nonzero and normalizes other coefficients to it, as implied by the manual.
• The REFERENCE_CORRECTION feature of CSBEND was not handling non-zero EPITCH or EYAW values, as reported by G. Penn (LBNL).

13.8.4 New and Modified Commands

• The ignore_elements command no longer results in a printout of all the ignored elements.
• Several improvements were made to the ion_effects command: (a) Changed binning for multi-function fits, so that only ions that are in range in both planes are counted. (b) Normalize kicks by the charge in the fit region, rather than the total charge. (c) Fixed some bugs with single Gaussian fit method. These changes were made by J. Calvery (APS).

13.8.5 Changes to Related Programs and Files

The elegant distribution includes many programs and scripts that perform computations with elegant output data, provide interfaces with other programs, or prepare data for use with elegant. These are listed in Section 8.

Changes to these tools in this release include

• The weightedBunch script now allows users to control the random number seed.
• The computeRBGGE and computeCBGGE programs now provide units for the generalized gradients.