Transcript 投影片 1
Injection
Injection Scenario
2-bumpers local closed orbit method and Lambertson
septum are used for vertical injection.
At the time of injection, circulating beam is bumped
and given a closed orbit towards the septum.
Injection beam at 25 MeV is directed from a linac to
the septum.
The whole beam is bumped back to the center orbit.
Accumulation scheme (phase-space painting) is
adopted.
Injected beam is damped to the center of the
circulating beam through radiation damping.
Repeat until required intensity is needed.
2 Bumpers Local Closed Orbit
Septum
Bumper 1
Bumper 2
( s) 2
xco (s)
i i cos (s) i
2 sin i 1
Conditionfor localizedclosed orbit :
21
and
2 1
1
2
11 cos 21 2 2 cos 0
11 sin 21 2 2 sin 0
How much angular deflection is needed?
Injection Scheme (Accumulation)
x 1.75
Septum
Total 9 Injections
B
Xco = 25 mm
x
X=0
25mA Linac
Average Beam Current 150mA
1mm
A = 18mm
5mm
4mm
2mm
Location of Bumpers
At thechosenlocationsfor thetwo bumpers:
21 179.3o
1
1.295
1
2
1.240
2
T heratioof the:
1
kickers'strength 1
At thechosenlocationfor theseptum:
s1 110o and s 2m
xco ( septum) 25m m
Kicker strength:
1 2 19m rad
Location of Bumpers
Location of Bumpers
Length of Septum = 0.2 m
Drift = 2.5 m
Bumper 1
Bumper 2
Bumper Strength
Bumper Strength
Kicker Strength
Due to the possibility of combining the injection and
fast extraction system, traveling wave kicker can
be used.
EL 1
1
k
c B
where B 0.0834[Tm]
L 0.1 m
c speed of light
1
E Gap ElectricField
Kicker Strength
x co 9 mm : k 7mrad
E 8.78[kV / cm]
x co 25 mm : k 12mrad E 23.0 [kV / cm]
Micrometerbeam size
gap 1 cm
Vgap 8 ~ 23 kV
Vgap can be reduced by using longer kicker
Kicker Strength
Septum Field Strength
Lambertson Septum is used for vertical injection.
z
Injection Beam
s
0.81m
1.15m
L=0.2m
0.81
o
tan
0
.
614
rad
or
35
.
2
1.15
1
Septum Field Strength
Bx L
B
Bx 0.26 T
25 MeV Injection