Improvements to Elements

• Added GROUP parameter to all elements. It allows assigning a common tag to elements. The tags are saved in the lattice and parameter files.

• The B2 (sextupole) parameter was added to the BUMPER element (which does time-dependent kicker simulation). Also, the N_KICKS parameter was added and must be non-zero if B2 is to have any effect.

• The CSRCSBEND now has a wake filter file capability, allowing the user to specify a filter function as a way to add, for example, shielding effects.

• The HISTOGRAM and WATCH (coordinate mode) now input parameter ``s'' giving the position of the element in the beamline. The HISTOGRAM element has a new parameter NORMALIZE with a default value of 1, which results in normalization of the histogram with the number of particles.

• Added steering capability to KQUAD and QUAD using an imposed dipole field, including (in the case of KQUAD) higher multipoles. (KQUAD and QUAD could already be used for steering by adjusting transverse position.)

• The MODRF (modulated rf cavity) now supports damping rates for AM and PM modulations.

• Several improvements were made to the NIBEND (Numerically Integrated BEND) element:
  • Added new fringe models: enge1, enge3, and enge5. These give 1st, 3rd, and 5th order expansions of three-coefficient Enge functions.
  • Added FP2 through FP4 parameters for NIBEND. They are used for direct input of Enge coefficients.
  • Added ADJUST_FIELD parameter, which provides a way to adjust the deflection angle to compensate for over- or under-bending due to fringe fields.
  • Added ADJUST_BOUNDARY parameter to allow turning off boundary position adjustment, which is the default method for adjusting the deflecting angle.
  • Misalignments are now supported.

• Matrices for the QUAD and SEXT elements may now have order up to 3. This can make a difference in momentum-dependent tune shifts and nonlinear dispersion computations.

• The RFCW element was changed extensively:
  • The N_KICKS parameter can now have a value other than 0 or 1. A non-zero value results in a drfit-kick-drift simulation with N_KICKS segments.
  • By default, the longitudinal and tranverse wakes are now applied at the location of the rf kick, which is a change from previous versions. Use the WAKES_AT_END parameter (set to 1) to revert to the previous behavior.
  • Added LSC parameter to the RFCW element, to provide simulation of longitudinal space charge in an accelerating cavity.

• Added FREQ_WAVEFORM and Q_WAVEFORM support to the RFMODE element, allowing a rudimentary method of detuning or tuning a mode at a programmed point in a simulation. This was requested by N. Sereno (ANL).

• The SCRIPT element has new USE_CSH and VERBOSITY controls. Setting USE_CSH=0 is much faster and should be used if C-shell is not needed.

• TRWAKE:
  • Added XFACTOR and YFACTOR parameters (which default to 1). These allow multiplying the wakes by factors.
  • Added TILT parameter.
  • Added XPOWER and YPOWER fields, which allows simulating transverse wakes due to asymmetric chambers (by setting XPOWER=0 and/or YPOWER=0). By default, XPOWER=1 and YPOWER=1.

• The ZLONGIT and ZTRANSVERSE elements now check that the input data is equispaced in frequency. This bug was found by T. Shaftan (BNL).
• Added FACTOR and REVERSE_TIME_ORDER parameters to ZLONGIT. The latter allows compensating for different sign conventions for the meaning of the longitudinal coordinate. (Recall that in elegant, a negative longitudinal coordinate indicates the head of the bunch.)