2.3.4 Rutherford Scattering
This experiment can be suitably performed using a vacuum chamber in
which are placed an source (presently 95Am241),
a gold foil target, and a detector. Surface Barrier detectors provide excellent detection
of the scattered particles. High counting rates are readily achieved so that many
measurements may be carried out in a relatively short time.
Some of the properties of Rutherford scattering that can be studied
are:
- The angular dependence of the number of scattered particles. Does this
depend on the Z of the target?
- Kinematics of elastic scattering. What is the angular dependence of the
energy of the scattered particles? Does this depend on the Z of the target? Several
targets may be mounted in the scattering chamber at once.
- The magnitude of the absolute cross section. What happens if you rotate
the target? How would you propose measurement of the target thickness?
- The apparatus may also be used to measure the stopping power for 's in various non-reactive gases.
References
- E. Rutherford, "The
Scattering of and Particles by Matter and the Strucuture of the Atom," Philos.
Mag. 21, 669 (1911 ). The is the original report of Rutherford's ideas about the
implications of the large angle scattering observed by Geiger and Marsden.
- H. Geiger and E. Marsden,
"On the Diffuse Reflection of the -Particles,"
Proc. Roy. Soc. (London) 82, 495 (1909). Scattered alphas counted by eye with a
microscope and a fluorescent screen of ZnS.
- H. Geiger, "The Scattering
of the -Particles by Matter," Proc.
Roy. Soc. (London) 83, 492 (1910). Companion to reference
above.
- J. J. Thomson, Philos. Mag. 44,
293 (1897). This was the competing theory at the time which attempted to account for the
scattering as a series of multiple scattering events from a cloud of postive charge.
- A. C. Melissinos, Experiments in Modern Physics, New York:
Academic Press (1966). This book as an excellent description of the apparatus and data
from a simple Rutherford scattering experiment, very much like our own except we use a
solid-state detector. QC33.M52.
- J. A. Earl, "Modified
Version of the MIT Rutherford Scattering Apparatus for Use in Advanced Undergraduate
Laboratories", Am. J. Phys. 34, 483 (1966).
- E. J. Burge, V. R. W. Edwards,
V. E. Lewis, and N. K. Ganguly, "Optimum Design of Student Experiments on Rutherford
Scattering", Am. J. Phys. 36, 351 (1968).
- J. L. Duggan, W. D. Adams, R.
J. Scroggs, and L. S. Anthony, "Charged-Particle Detection Experiments for the Modern
Physics Laboratory". Am. J. Phys. 35, 631 (1969).
- J. C. Ramage, J. McKeown, and
K. W. D. Ledingham, "A Convincing Demonstration of the Rutherford csc3#3 Law,"
Am. J. Phys. 43, 51 (1975). Discusses data set obtained with a Si detector
including the necessary corrections.
- G. C. Kyker, "Resolving
Time Effect on Counting Statistics", Am. J. Phys. 49, 561 (1981).
- L. D. Northcliffe and R. F. Schilling, "Range and Stopping Power
Tables for Heavy Ions", Nuclear Data Tables 7, 233 (1970). A thorough review
of stopping power of charged particles in gases and solids with tables. QC173.N78 in
ENGR STOR(age) *
- J. B. Marion and B. A.
Zimmerman, "Multiple Scattering of Charged Particles", Nucl. Instrum. Methods 51,
93 (1967).
- P. J. Ouseph and A. Mostovych,
"An Experiment to Measure Range, Range Straggling, Stopping Power, and Energy
Straggling of Alpha Particles in Air", Am. J. Phys. 46, 742 (1978).
- J. F. Ziegler and V. Littmark, Handbook of Stopping Cross-sections
for Energetic Ions in All Elements, New York: Pergamon Press, 1980. QC 702.Z53.
- J. F. Ziegler, The Stopping and Range of Ions in Solids, New
York: Pergamon Press, 1985. QC794.S8Z534.
- W. J. Price, Principles of Radiation Detection, New York:
McGraw-Hill Co., 1964. QC787.C6P7.
- G. Dearnaley and D. C. Northrop, Semiconductor Counters for Nuclear
Radiations, London: Spon (1963). QC787.C6D4.
- The Whys and Wherefores of Charged
Particle Detector Spectrometry (1985)
* Missing from archive 6/00
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