6.4 BEAM-POSITION PROBLEMS
NO.
SYMP TOM
PROB A BLE CAUSE
COR REC TION
1
High volt age, emis sion cur rent, and fil a -
ment cur rent are all nom i nal, but ex ces -
sive lon gi tu di nal cur rent is re quired to
cen ter beam in pocket. (See power sup ply
man ual for nom i nal op er at ing val ues.)
(a) Weak per ma nent mag net.
(a) Check beam-spot po si tion with 0 A lon -
gi tu di nal de flec tion cur rent ap plied. If spot
is too far to ward rear of source (see Fig -
ure 6-1), re place per ma nent mag net or
have it regaussed.
(b) Lon gi tu di nal de flec tion coil is par tially
shorted in ter nally.
(b) Test in ter nal re sis tance of lon gi tu di nal
coil. Re place coil as sem bly if mea sured
re sis tance is not be tween 2.2 and 2.4
ohms.
2
High volt age, emis sion cur rent, and fil a -
ment cur rent are all nom i nal, but the beam
is not cen tered lon gi tu di nally.
(a) Lon gi tu di nal de flec tion cur rent is set to
in cor rect value.
(a) Ad just lon gi tu di nal de flec tion cur rent.
(b) The per ma nent mag net is weak.
(b) Check beam-spot po si tion with 0 A lon -
gi tu di nal de flec tion cur rent ap plied. If spot
is too far to ward rear of source (see Fig -
ure 6-1), re place per ma nent mag net or
have it regaussed.
3
High volt age, emis sion cur rent, and fil a -
ment cur rent are all nom i nal, but beam
spot is ei ther off cen ter or asym met ri cal in
the lat eral axis.
(a) Lat eral de flec tion coil is en er gized.
(a) Check to see whether any lat eral de -
flec tion cur rent is be ing ap plied. If so, ad -
just it to 0 A.
(b) The mid point of the fil a ment is not
aligned ex actly be tween the pole pieces.
(b) Make sure that the fil a ment is po si -
tioned cor rectly and that it is not warped or
sag ging.
(c) Pole pieces or pole piece ex ten sions
are dam aged.
(c) Ex am ine these parts for signs of dam -
age; re place parts as nec es sary.
(d) Pole pieces are not mounted tight
against per ma nent mag net.
(d) Loosen screws se cur ing pole pieces to
coil hous ing and source base plate. Re ad -
just po si tion of pole pieces as needed to
en sure that both are touch ing the mag net,
then retighten screws to 8 ft.-lbs.
(e) Pole piece ex ten sions are not ad justed
sym met ri cally.
(e) Check po si tions of ex ten sions and ad -
just them as nec es sary (see sec tion 3.2
for in struc tions).
(f) In ter fer ence from an other source
mounted in same cham ber.
(f) Make sure that mag netic shield ing is
cor rectly in stalled be tween the sources
(see sec tion 2.4 for in struc tions).
(g) Ei ther the two lat eral de flec tion coils
are shorted to gether, or one of them is
shorted in ter nally or to ground.
(g) Using ohm me ter, test re sis tance be -
tween the two lat eral ter mi nals of the coil
as sem bly and be tween each of these ter -
mi nals and ground. There should be in fi -
nite re sis tance be tween ei ther ter mi nal
and ground. Re sis tance be tween the two
ter mi nals should mea sure be tween 3.0
and 3.2 ohms. Re place coil as sem bly if
lat eral coil fails ei ther test.
4
Ad justing beam-position con trols has no
ef fect on beam po si tion in ei ther axis.
(a) No de flec tion cur rent is be ing ap plied
to coils.
(a) Coil leads are dis con nected or shorted
in ter nally. Make sure they are prop erly
con nected. Then check them for shorts.
Troubleshooting
6-6
0101-9004-0A
STIH-270-2PT
Содержание Temescal SuperSource2 STIH-270-2PT
Страница 54: ...Operation 3 18 0101 9004 0A STIH 270 2PT...
