This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Two Photon Angular Correlations Experiments in Modern Physics (P451) You will use coincidence timing techniques along with a single channel analyzer to study correlated photons produced by both 22 Na and 60 Co. Introduction Both 22 Na and 60 Co produce (nearly) coincident photons; however, the physics processes governing these two productions are entirely different. In the case of 22 Na the photons are produced by annihilation of a + emitted from the isotope. The process is + + - + , where the - is simply an electron in the matter surrounding the nucleus. The two photos emerge simultaneously and, to conserve momentum, in opposite directions. One can verify this with the apparatus. The 60 Co nucleus undergoes -decay to 60 Ni. This unstable Ni nucleus then decays through two sequential photon emissions. (See Ref. [1, 2, 3] for more details.) The intermediate nuclear isotope has an extremely short half life on the order of picoseconds; therefore, these two photons are emitted nearly simultaneously. Since the half-life of the intermediate state is so short, the polarization of the nucleus is preserved from the time the first photon is emitted until the second photon is emitted. Therefore information about the angular momentum of the unstable nucleus insecond photon is emitted....
View Full Document
This document was uploaded on 01/20/2012.
- Fall '09