Relativistic Dynamics
Measurement of the velocity-momentum-energy relations of relativistic electrons and determination of e/m. Energetic electrons from the beta decay of 90SR and its decay product 90Y are sorted according to momentum by a 180 degree magnetic spectrograph, passed through a velocity selector, and detected by a PIN diode detector.
Plots of momentum and energy vs. velocity are compared with the theoretical relations of classical and relativistic dynamics, and the value of the ratio e/m is derived from the data.
Lab Guide (PDF)

Relativistic dynamics lab. (Image courtesy of Junior Lab staff.)
References
Emilio, Segre. "Radioactive Decay." In Experimental Nuclear Physics. Vol. 1. New York, NY: Wiley, 1953, pp. 1-39.
———. "Passage of Heavy Particles through Matter." Section 2.1B-D in Experimental Nuclear Physics. Vol. 1. New York, NY: Wiley, 1953, pp. 231-252.
Evans, Robley Dunglison. "Beta-Ray Spectra." Chapter 17 in The Atomic Nucleus. New York, NY: McGraw-Hill, 1955, pp. 536-566.
Bleuler, Ernst, and George J. Goldsmith. "Range and Energy Loss of Alpha Particles," and "Radiations of Cu(64) (Zn(65))." Experiment 19 and 23 in Experimental Nucleonics. New York, NY: Rinehart, 1952, pp. 275-282 and 3341-354.
Ritson, David M., "General Properties of Particles and Radiation." Chapter 1 in Techniques of High Energy Physics. New York, NY: Interscience Publishers, 1961, pp. 1-53.
England, J. B. A. "Magnetic Spectrometers for Beta Particles and Electrons." Section 4.2 in Techniques in Nuclear Structure Physics. Vol. 2. New York, NY: Wiley, 1974, pp. 349-383. ISBN: 0470241616.
Evans, Robley Dunglison. "Statistical Fluctuations in Nuclear Processes." Chapter 26 in Atomic Nucleus. New York, NY: McGraw-Hill, 1955, pp. 746-772.