Post on 23-Mar-2016
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But have never been used to study the structure of short-lived radioactive nuclei.
a large accelerator complexincluding a cooler ring and a collider
M. Wakasugi, et al., Nucl. Instr. and Meth. A 532 (2004) 216-233
Total length 650mmTrapping region 〜 260mm
42 thin electrodes are stacked every 11 mm.
Be(t=1mm) window
110 mm
35 mm
Inside the SCRIT
dd
el
dd
Mfr F0
C(q)2
fr 1
12k1M
sin2 2
k2k1
M: Mass of nucleus
F0C(q)
F0
C(q) = 4 (r) sinqrqr
r20
dr
(r) = 1
2 2rF0
C(q)sin(qr)q0
dr
| Fc(q
) |2
|Fc(
q)|2
Momentum transfer (MeV/c)
20 30 40 50 60 70 801E-16
1E-14
1E-12
1E-10
1E-8
1E-6
1E-4
0.01
1
elas
tic c
ross
sect
ion
(bar
n)
scattering angle (degree)
100 MeV 300 MeV 500 MeV 800 MeV
Energy of e- beam
I. Externally injected ions trapped ?
II. Luminosity can be reached to 1027 s-1cm-2 ?
Those three calorimeters for the energy of scattering electrons
Residual gases
Scattered electron
PRL 100, 164801 (2008)
PRL 102, 102501 (2009)
Non-uniform distribution
40 44 48 52 56 60 64 68 72 760
2
4
6
8
10
12lu
min
osity
(1025
cm-2
s-1)
beamcurrent (mA)
Higher luminosity can be expected with higher beam current.
ions(a)
(c)
(b)
(d)
(e)
SCRIT Longitudinal potential
SCRIT Longitudinal potential
SCRIT Longitudinal potential
SCRIT Longitudinal potential
SCRIT Longitudinal potential
ions
ions trapped
ions
ions
Elastic electron scattering
e
e’
q
0+
0 4 82 6 10r (fm)
c (r
)(fm
-3)x
10-2
4He
12C
16O
40Ca48Ca
208Pb
elastic scatteringcross section is largest (up to medium momentum transfer region)charge density distribution (charge form factor)
beyond mean-square charge radius by IS,muonic X-ray| F
c(q) |
2
|Fc(
q)|2
Momentum transfer (MeV/c)
2 s2 s
Cs ions Cs ionsCs ions
Cycle #1 Cycle #2 Cycle #3 Cycle #4
Total Cycle number is 18 in 2 seconds measurement
110 ms