摘要:

Prepared at the request of the AAPT Committee on Resource Letters; supported by a grant from the National Science Foundation.This is one of a series of Resource Letters on different topics, intended to guide college physicists to some of the literature and other teaching aids that may help them improve course contents in specified fields of physics. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter on some of the main subjects of interest. Comments and suggestions concerning the content and arrangement of letters as well as suggestions for future topics will be welcomed. Please send such communications to Professor Arnold Arons, Chairman Resource Letter Committee, Department of Physics, Amherst College, Amherst, Massachusetts.Notation:The letterEafter an item number indicateselementarylevel, useful principally for freshman liberal arts through sophomore physics courses; the letterIindicatesintermediate(junior, senior) level; and the letterAindicatesadvancedmaterial principally suited for senior, graduate study. An asterisk (*) indicates items particularly recommended for introductory study.Additional copies:Available from American Institute of Physics, 335 East 45 Street, New York, New York 10017. When ordering, request Resource Letter Scy-1 and enclose a stamped return envelope. A small booklet containing reprints of some of the fundamental references will soon be available for purchase from the American Institute of Physics.

ISSN:0002-9505    

DOI:10.1119/1.1970157

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

The ray-tracing method is used to discuss Gaussian optics. After proving that Gaussian optics can be described by matrices, some often-used general formulas for telescopic and focusing systems are derived. This formalism is then used to solve several problems. They are selected to make the reader familiar with the application of the matrix representation of Gaussian optics and to acquaint him with some optical systems that are very useful but not well known among physicists who use optical methods only occasionally.

ISSN:0002-9505    

DOI:10.1119/1.1970159

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A Mössbauer-effect apparatus, suitable for either lecture demonstration or inclusion in an undergraduate teaching laboratory, is described. Use of a rotating tilted disk to provide linear motion between source and absorber simplifies the construction and calibration of the experimental equipment. Some features are as follows: calibration of velocity by timing rotations of the wheel with a stopwatch, provision of a large-scale motion which graphically illustrates the first-order relativistic Doppler shift and its effect on monochromatic radiation, and sufficient precision to measure the nuclear Zeeman splitting in iron of theFe57mtransition. Construction details, as well as instructions for the use of the equipment, are given.

ISSN:0002-9505    

DOI:10.1119/1.1970138

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A review of the chain of experiments whose results were finally explained by Compton's discovery of the Compton effect shows that these experiments were not solely in the field of x rays. The studies of the scattering of high-energy gamma rays of radium had presented physicists with the puzzle that scattered gamma rays were distinctly less penetrating than were those that had not been scattered, and that the amount of this “softening” of the scattered gamma rays was dependent on both the initial “hardness” of the gamma rays and on the scattering angle. Many of the experimental facts of the Compton effect were well known from the studies of scattering of gamma rays some years before the effects were observed with x rays. Compton's interest in the problem was apparently greatly stimulated by his own experiments on the scattering of gamma rays.However, since the first detailed and convincing experimental verification of several of the consequences of Compton's hypothesis came from experiments with x rays, one may not be aware of the important role played by gamma-ray experiments in the steps leading to the discovery.

ISSN:0002-9505    

DOI:10.1119/1.1970139

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

An experiment is described in which the magnitude and angle dependence of the wavelength shift of Compton scattered photons can be determined. The equipment necessary for the experiment is simple and inexpensive. The experiment is a modified version of the “absorption curve” type of study which as early as 1904 (nearly 20 years prior to Compton's discovery) showed the wavelength shift of scattered gamma-ray photons.

ISSN:0002-9505    

DOI:10.1119/1.1970140

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A description is given of an advanced laboratory experiment in which the student is able to verify the Compton effect in detail. The experiment allows the student to examine the angular dependence of the energy of the Compton-scattered photon and of the Compton-scattered electron. The simultaneity of the two scattered “particles” is the key to the experimental observations. The results allow one to directly verify conservation of energy for single-photon scattering events. The agreement of experiment and theory then allow one to conclude that momentum is also conserved in these encounters.

ISSN:0002-9505    

DOI:10.1119/1.1970141

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

After a brief discussion of space inversion and time inversion, the distinction between magnetic and nonmagnetic crystal classes is illustrated by reference to cubic lattices. The appearance of “forbidden” effects in various crystal classes is discussed and recent experimental work on pyromagnetism, the magnetoelectric effect and piezomagnetism in antiferromagnetic materials is reviewed.

ISSN:0002-9505    

DOI:10.1119/1.1970142

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

Assuming that the fields of a moving-point charge as computed from the retarded Liénard-Wiechert potentials give valid descriptions for moving electrons, it is shown that no net second-order static electric field of the type discussed by Rosser appears on the axis of a charge-neutral circular loop carrying a steady current. An argument is given for the nonexistence of such “residual” electric fields around any closed, charge-neutral region in which the current flow is time independent.

ISSN:0002-9505    

DOI:10.1119/1.1970143

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

Transition probabilities for the forced, undamped quantum harmonic oscillator are obtained by expressingS-matrix elements entirely in terms of Heisenberg states and operators. The application of this method to this elementary-field theoretic model provides a simple example of the contraction technique of modern field theory whereby particles are converted into their corresponding currents. This problem was recently analyzed in the interaction picture from a pedagogical point of view and the treatment presented here is given in the same spirit.

ISSN:0002-9505    

DOI:10.1119/1.1970144

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A detailed study of the kinematics of neutron-proton, proton-neutron and neutron-neutron scattering (henceforth calledn-p,p-nandn-nscattering, respectively) reveals a significant difference in the elastic differential cross section in laboratory directions corresponding to the near backward direction in the center of mass system. Based on the finiten-pmass difference, then-pscattering cross section goes to ∞ at 86°59.5′, thep-nscattering shows a slight amount of backward scattering and then-nscattering cross section equals zero for all laboratory angles greater than 90°. Most treatments ofn-pscattering limit the discussion of the kinematics of the scattering process to a neutron-proton mass ratio to unity. It is of interest to consider the extent to which the actual difference in mass influences the angular distribution of the scattered particle. It is the purpose of this paper to discuss the consequences of the small, but non-negligible,n-pmass difference in the kinematics of scattering. Although it is not possible to obtain free neutrons at rest and hencep-nscattering cannot be observed in the laboratory, it, withn-nscattering is discussed here to get an idea as to what the kinematics ofn-pscattering would have been if neutrons were lighter than protons and if the neutron mass were exactly equal to the proton mass.

ISSN:0002-9505    

DOI:10.1119/1.1970145

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP