Csh Problem using spaces in string variables

I have done something like this

set phases = "a b"
set  phases = "phases="$phases
echo $phases

I get

phases=a

instead of

phases=a b

move your quotes.

set  phases = "phases=$phases"

not sure what your trying to do by if you just need to echo the value do it this way

echo "phases=$phases"

Hopefully, this question is answered as well on your other post.

As a rule of thumb think of the single quote (') as a string were all the characters loose their extra special meaning, therefore, symbols like $,",*, etc, are interpreted by their face value at the shell.

I need to create the variable containing the string so that I can use it to run a program from within the csh script.

/nethome/chrisd/HSeis/TommyCD/TommyCD-1101/bin/raytrac \
   vmod=npt02-z30.vmod \
   srfile=jcdint.sc \
   rcfile=jcdint.rc \
   phases="SP FS" \
   level=twop \
   format="X T" \
   dtau=0.1 \
   mdacc=0.5 \
   mindist=0.2 \
   maxitertp=25 \
   ray=npt02-z30.ry \
   out=npt02-z30.tx \
   vrb=medium |& tee npt02-z30.log