Compton Scattering

The general review of cross section formulas for the photoelectric effect, Compton scattering, pair and triplet production is presented in the intermediate and high photon energy spectrum for carbon (Z=6). Using the classical Gaussian regression method, the empirical correction functions for the theoretical cross section formulas are calculated based on the existing experimental data. The simple formulas can be used to calculate the cross sections of four main radiation effects with a good accuracy. The proposed formulas are enough for practical calculations in the excel spreadsheet in e.g. radiation protection applications or radiation shields designing.

The gamma ray energy absorption ( EABF) and exposure buildup factors ( EBF) have been calculated for some essential amino acids, fatty acids and carbohydrates in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameter geometric progression (G-P) fitting approximation has been used to calculate both EABF and EBF. Variations of EABF and EBF with incident photon energy, penetration depth and weight fraction of elements have been studied. While the significant variations in EABF and EBF for amino acids and fatty acids have been observed at the intermediate energy region where Compton scattering is the main photon interaction process, the values of EABF and EBF appear to be almost the same for all carbohydrates in the continuous energy region. It has been observed that the fatty acids have the largest EABF and EBF at 0.08 and 0.1 MeV, respectively, whereas the maximum values of EABF and EBF have been observed for aminoacids and carbohydrates at 0.1 MeV. At the fixed energy of 1.5 MeV, the variation of EABF with penetration depth appears to be independent of the variations in chemical composition of the amino acids, fatty acids and carbohydrates. Significant variations were also observed between EABF and EBF which may be due to the variations in chemical composition of the given materials.

Example problems on photoelectric effect, and Compton effect. Content typical of Modern Physics textbook. Introduction to the basic physics involved in PV cells for power generation. UG level.

Solved example problems from Mahesh C. Jain textbook 'QMs A Textbook for UGs'. Users of this file may get the theory from any UG Modern Physics textbook.

Any errors and omissions apologies in advance.

Omega Photoproduction at Graal

O. Bartalini, V. Bellini, J. P. Bocquet, M. Castoldi, A. D’Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, G. Gervino, F. Ghio, B. Girolami, A. Giusa, M. Guidal, E. Hourany, V. Kouznetsov, R. Kunne, A. Lapik, P. Levi Sandri, A. Lleres, D. Moricciani, V. Nedorezov, L. Nicoletti, C. Randieri, D. Rebreyend, F. Renard, N. V. Rudnev, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, A. Zabrodin, A. Zucchiatti (2003) - GDH 2002, Proceedings of the Second International Symposium on the Gerasimov-Drell-Hearn Sum Rule and the Spin Structure of the Nucleon, Genova (Italy), 3-6 July 2002. Published in World Scientific Publishing Co. Pte. Ltd., June 2003, pp. 327-332, doi: 10.1142/9789812705167 0046

Abstract
A tagged and polarized Compton backscattered photon beam is produced at the GRAAL facility in the energy range from 0.5 GeV up to 1.5 GeV. We present new very preliminary results on beam polarization asymmetry Σ for the ω photoproduction on the proton. These results confirm the relevance of resonance contributions to polarization observables.

In this paper, we bring the Zitterbewegung electron model and our photon model together to provide a classical explanation of the scattering of photons by electrons. We understand electron-photon interference (which is usually referred to as Compton scattering) as two electromagnetic oscillations interfering (classically) with each other. While developing the model, we offer some reflections on the Uncertainty Principle (Copenhagen interpretation of quantum mechanics). We conclude there is no need for it: God doesn’t play dice.

The book deals with the complex history of six main mental models of light quanta: the Newtonian corpuscular model, the singularity model, the binary model of photons, the wave packet model, the semiclassical model and, finally, QED. Klaus Hentschel portrays the emergence and development of concepts as layered semantic accretion as a paradigm for long-term, multilayered processes involving a gradual formation of signification and shifting over time. The history of the concept of light quanta, featuring Isaac Newton, Max Planck, Albert Einstein, Johannes Stark, Robert Millikan, Gilbert N. Lewis and dozens of later physicists is taken as an insructive example of this process. The book is pertinent for physicists, historians and philosophers of physics, cognitive psychologists and for all people interested in the formation of our ideas and mental models of what is today called 'photons'.

The photon is demystified in energy wave theory as a transverse wave packet of energy, resulting from the vibration of particles that are responding to waves that naturally travel the universe. In earlier works in the theory, the photon was accurately modeled mathematically with the same wave properties that govern the creation of particles and their forces. In this paper, the photon’s behavior is further explained to match various photon experiments, describing the mechanism for the creation and absorption of transverse waves.

Abetract—The scattering of X-rays and v-rays are events that have strong dependencies on the polarization ofthe incident and scattered photons. Because of this, scattering problems that can be solved without explicit reference to the state of polarization of the incident and scattered radiation are exceptional. This article reviews available information on polarizationeffects arising when photons in the X-ray and v-ray regime undergo photoelectric effect, coherent (Rayleigh) scattering and incoherent (Compton) scattering by atomic electrons. In addition to descriptions and discussion of these effects, we study the backscattering of y-rays from an infinite thickness target excited with a plane slant monodirec-tional and monochromatic source, using the Boltzmann transport theory and the mathematical representation ofpolarization introduced by Stokes. Results from this model, for both unpolarized and polarized y-ray sources, are compared with computations performed neglecting or averaging polarization effects, showing the limitations of such approximations.

The observable parameters of the electron indicate unambiguously that its gravitational background should be the Kerr-Newman solution without horizons. This background is not flat and has a non-trivial topology created by the Kerr singular ring. This ring was identified with a closed gravitational string. We discuss the relation of this string to the closed heterotic string of the low energy string theory and show that travelling waves along the KN string give rise to the Dirac theory of electron. Gravitational strings form a bridge between gravity and quantum theory, indicating a new way to consistent Quantum Gravity. We explain the pointlike experimental exhibition of the electron and argue that the predicted closed string may be observed by the novel experimental method of the "nonforward" Compton scattering.

The vertical beam profile at the PETRA positron storage ring has been measured using a laserwire scanner. A laserwire monitor is a device which can measure high brilliance beam profiles by scanning a finely focused laser beam noninvasively across the charged particle beam. Evaluation of the Compton scattered photon flux as a function of the laser beam position yields the transverse beam profile. The aim of the experiment at PETRA is to obtain the profile of the positron beam at several GeV energy and several nC bunch charge. Key elements of laserwire systems are currently being studied and are described in this paper such as laser beam optics, a fast scanning system and a photon calorimeter. Results are presented from positron beam profile scans using orbit bumps and a fast scanning scheme.

We review known and discuss new signatures of high-intensity Compton scattering assuming a scenario where a high-power laser is brought into collision with an electron beam.  At high intensities one expects to see a substantial redshift of the usual kinematic Compton edge of the photon spectrum caused by the large, intensity-dependent effective mass of the electrons within the laser beam. Emission rates acquire their global maximum at this edge while neighboring smaller peaks signal higher harmonics. In addition, we find that the notion of the center-of-mass frame for a given harmonic becomes intensity dependent. Tuning the intensity then effectively amounts to changing the frame of reference, going continuously from inverse to ordinary Compton scattering with the center-of-mass kinematics defining the transition point between the two.

TeV emission from BL Lacertae (BL) objects is commonly modeled as synchrotron self-Compton radiation from relativistically moving homogeneous plasma blobs. In the context of these models, the blob Lorentz factors needed to reproduce the TeV emission corrected for absorption by the diffuse infrared background are large (δ>~50). The main reason for this is that stronger beaming eases the problem of the lack of ~IR-UV synchrotron seed photons needed to produce the deabsorbed ~few TeV peak of the spectral energy distribution. However, such high Doppler factors are in strong disagreement with the unified scheme, according to which BLs are FR I radio galaxies with their jets closely aligned to the line of sight. Here, motivated by the detection of subluminal velocities in the subparsec-scale jets of the best studied TeV blazars, Mrk 421 and Mrk 501, we examine the possibility that the relativistic flows in the TeV BLs decelerate. In this case, the problem of the missing seed photons is solved because of upstream Compton scattering, a process in which the upstream energetic electrons from the fast base of the flow ``see'' the synchrotron seed photons produced in the slow part of the flow relativistically beamed. Modest Lorentz factors (Γ~15), decelerating down to values compatible with the recent radio interferometric observations, reproduce the ~few TeV peak energy of these sources. Furthermore, such decelerating flows are shown to be in agreement with the BL-FR I unification, naturally reproducing the observed BL/FR I broadband luminosity ratios.

In this paper a practical solution to perform spectral analysis of diagnostic X-ray beams is described, based on a miniaturized Compton selection chamber (CSC) using a Si-PIN detector. Results are compared with those obtained with a first prototype of CSC based on nitrogen cooled high purity germanium (HPGe) detector. With this method, the direct X-ray spectrum is Compton scattered inside the CSC, collected by a solid-state detector and reconstructed using a simplified scattering matrix experimentally determined. The results obtained will be compared with a reference standard, represented by direct spectra acquired with an HPGe detector in a laboratory facility, not applicable for on-field measurements.