1. 1896 Discovery of radioactivity
2. 1898 Isolation of radium
3. 1905 Special theory of relativity
4. 1909 particle shown to be He nucleus
5. 1911 Nuclear atom
6. 1912 Development of cloud chamber
7. 1913 Planetary atomic model
8. 1914 Nuclear charge determined from X rays
9. 1919 Artificial transmutation by nuclear reactions
10. 1919 Development of mass spectrometer
11. 1925 Intrinsic spin proposed
12. 1926 Quantum mechanics developed
13. 1928 Theory of radioactivity
14. 1930 Neutrino hypothesis
15. 1931 First electrostatic accelerator
16. 1931 First linear accelerator
17. 1932 First cyclotron
18. 1932 Discovery of deuterium
19. 1932 Discovery of positron
20. 1932 Discovery of neutron
21. 1932 Proton-neutron nuclear model
22. 1932 First nuclear reaction using accelerator
23. 1934 Discovery of artificial radioactivity
24. 1934 Theory of radioactivity
25. 1935 Meson hypothesis
26. 1936 Compound nucleus theory proposed
27. 1937 Discovery of lepton in cosmic rays
28. 1938 Thermonuclear fusion proposed as source of energy in stars
29. 1939 Liquid-drop model of fission
30. 1940 Production of first transuranium element
31. 1941 First betatron, magnetic induction electron accelerator
32. 1942 First controlled fission reactor
33. 1944 Phase stability developed for synchrotron
34. 1945 First fission bomb tested
35. 1946 Big Bang cosmology
36. 1946 Development of nuclear magnetic resonance
37. 1947 Development of radiocarbon dating
38. 1947 First proton synchrocyclotron, 350 MeV
39. 1947 Discovery of meson
40. 1948 First linear proton accelerator, 32 MeV
41. 1949 Shell model of nuclear structure
42. 1949 Development of scintillation counter
43. 1952 First proton synchrotron, 2.3 GeV
44. 1952 First thermonuclear bomb tested
45. 1953 Strangeness hypothesis
46. 1953 Collective model of nuclear structure
47. 1953 First production of strange particles
48. 1955 Discovery of antiproton
49. 1956 Experimental detection of neutrino
50. 1956 Parity violation in weak interactions
51. 1958 Recoilless emission of gamma rays
52. 1959 26-GeV proton synchrotron
53. 1964 Observation of CP violation in decay
54. 1964 Quark model of hadrons
55. 1967 Initial opeartion of SLAC accelerator for 20-GeV electrons
56. 1967 Electroweak model proposed
57. 1970 Charm hypothesis
58. 1971 Proton-proton collider
59. 1972 500-GeV proton synchrotron
60. 1974 particle discovered and charmed quark confirmed
61. 1975 Discovery of lepton
62. 1977 particle discovered and bottom quark confirmed
63. 1983 Operation of proton-antiproton collider at 300 GeV
64. 1983 Discovery of weak bosons and

Source: Introductory Nuclear Physics, Kenneth S. Krane