EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH

Sectormap output

The flag "sectormap" on the Twiss command (together with an element selection via select,flag=sectormap,...) causes a file "sectormap" to be written.

For each user-selected element, it contains the user-selected coefficients of the kick vector K (6 values), of the first-order map R (6 x 6 values) and of the second-order map T (6 x 6 x 6 values)

The sector file is the output of a standard TFS table, which means that the set of columns of interest may be selected through a MAD-X command such as the following:

select,flag=my_sect_table,column=name,pos,k1,r11,r66,t111;

Each line of the sectormap file contains for each selected element, the set of chosen K,R,T matrix coefficients:

@ NAME %13s "MY_SECT_TABLE"
@ TYPE %09s "SECTORMAP"
@ TITLE %08s "no-title"
@ ORIGIN %19s "MAD-X 3.04.62 Linux"
@ DATE %08s "18/12/08"
@ TIME %08s "10.33.58"
* NAMEPOSK1R11R66T111
$ %s%le%le%le %le%le
"FIVECELL$START" 00110
"SEQSTART" 0 0 1 1 0
"QF.1" 3.1-1.305314637e-051.04222474510
"DRIFT_0"3.2657.451656548e-21110
"MSCBH"4.365-1.686090613e-150.999997275510.006004411526
"CBH.1"4.3650110
"DRIFT_1"5.519992305-6.675347543e-21110
"MB"19.720007692.566889547e-181.0000000911-4.135903063e-25
"DRIFT_2"21.17999231-1.757758802e-20110
"MB"35.380007692.822705549e-181.0000000911-4.135903063e-25
"DRIFT_2"36.839992312.480880093e-20110
"MB"51.040007693.006954115e-181.0000000911-4.135903063e-25
"DRIFT_3"52.21-4.886652187e-20110
..................
..................
..................

Of course, the select statement can be combined with additional options to filter-out the list of elements, such as in the following statement, which for instance only retains drift-type elements:

select,flag=my_sect_table,class=drift,column=name,pos,k1,r11,r66,t111;

K coefficients range: K1... K6

R coefficients range:
R11...R61
R12...R62
.........
R61...R66

T coefficients range:
T111...T611
T121...T621
.........
T161...T661
T112...T612
.........
T166...T666

In the above notation, Rij stands for "effect on the i-th coordinate of the j-th coordinate in phase-space", whereas Tijk stands for "combined effect on the i-th coordinate of both the j-th and k-th coordinates in phase-space" along the lattice.

The maps are the accumulated maps between the selected elements. They contain both the alignment, and field errors present. Together with the starting value of the closed orbit (which can be obtained from the standard twiss file) this allows the user to track particles over larger sectors, rather than element per element. A typical usage therefore lies in the interface to other programs, such as TRAIN.
hansg, May 8, 2001