5. M. Wakasugi, et al., Nucl. Instr. and Meth. A 532 (2004) 216-233 Total length 650mm Trapping region 〜 260mm 42 thin electrodes are stacked every 11 mm. Be(t=1mm) window 110 mm 35 mm Inside the SCRIT

6. M ： Mass of nucleus | F c (q) | 2 Momentum transfer (MeV/c)

7. Energy of e - beam

10. Residual gases

11. Scattered electron

12. PRL 100, 164801 (2008)

13. PRL 102, 102501 (2009)

15. Non-uniform distribution

20. ions (a) (c) (b) (d) (e) SCRIT Longitudinal potential ions trapped ions

21. Elastic electron scattering e e’ q 0+0+ 04 8 2 6 10 r (fm)  c (r)(fm -3 )x10 -2 4 He 12 C 16 O 40 Ca 48 Ca 208 Pb elastic scattering cross 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 Momentum transfer (MeV/c)

22. Cs ions Cycle #1Cycle #2Cycle #3Cycle #4 Total Cycle number is 18 in 2 seconds measurement 110 ms