EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH
Element Input Format
All physical elements are defined by statements of the form
label: keyword {,attribute};
Example:
QF: QUADRUPOLE,L=1.8,K1=0.015832;
where
- label
is a name to be given to the element (in the example QF),
- keyword
is an element type keyword (in the example QUADRUPOLE).
- attribute
normally has the form
"attribute-name=attribute-value" or "attribute-name:=attribute-value"
(except for multipoles).
- attribute-name
selects the attribute, as defined for the element type keyword
(in the example L and K1).
- attribute-value gives it a value
(in the example 1.8 and 0.015832). The value may be specified
by an expression. The "=" assigns the value on the right to the
attribute at the time of definition, regardless of any further change
of the right hand side; the ":=" re-evaluates the expression at the right
every time the attribute is being used. For constant right hand sides,
"=" and ":=" are of course equivalent.
Omitted attributes are assigned a default value, normally zero.
A special format is used for a multipole:
m:multipole, kn= {kn0, kn1, kn2, ..., knmax},
ks= {ks0, ks1, ks2, ..., ksmax};
where kn and ks give the integrated normal and skew strengths, respectively.
The commas are mandatory, each strength can be an expression; their position
defines the order. example:
m:multipole, kn={0,0,0,myoct*lrad}, ks={0,0,0,0,-1.e-5};
defines a multipole with a normal octupole, and a skew decapole component.
To know the current maximum order, enter the command
help,multipole;
and count.
hansg,
January 24, 1997