Measurement of deflection on germanium and gold prisms using 1.7 MeV laser Compton scattering γ -rays

Kawasaki, T.; Naito, Susumu; Sano, Y.; Hayakawa, Takehito; Shizuma, T.; Hajima, Ryoichi; Miyamoto, Shuji

doi:10.1016/j.physleta.2017.07.030

Cited by 9 publications

(4 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some frequencies of electromagnetic radiation, for example the visible spectrum, can be focused using refractive and reflective optics. However, the refractive index decreases with increasing photon energy, meaning these traditional focusing optics are not applicable to gamma energies [ 20 ]. Therefore, an algorithmic method is presented instead.…”

Section: Introductionmentioning

confidence: 99%

Radioactive Source Localisation via Projective Linear Reconstruction

White

Wood

Martin

et al. 2021

Sensors

View full text Add to dashboard Cite

Radiation mapping, through the detection of ionising gamma-ray emissions, is an important technique used across the nuclear industry to characterise environments over a range of length scales. In complex scenarios, the precise localisation and activity of radiological sources becomes difficult to determine due to the inability to directly image gamma photon emissions. This is a result of the potentially unknown number of sources combined with uncertainties associated with the source-detector separation—causing an apparent ‘blurring’ of the as-detected radiation field relative to the true distribution. Accurate delimitation of distinct sources is important for decommissioning, waste processing, and homeland security. Therefore, methods for estimating the precise, ‘true’ solution from radiation mapping measurements are required. Herein is presented a computational method of enhanced radiological source localisation from scanning survey measurements conducted with a robotic arm. The procedure uses an experimentally derived Detector Response Function (DRF) to perform a randomised-Kaczmarz deconvolution from robotically acquired radiation field measurements. The performance of the process is assessed on radiation maps obtained from a series of emulated waste processing scenarios. The results demonstrate a Projective Linear Reconstruction (PLR) algorithm can successfully locate a series of point sources to within 2 cm of the true locations, corresponding to resolution enhancements of between 5× and 10×.

show abstract

Section: Introductionmentioning

confidence: 99%

Radioactive Source Localisation via Projective Linear Reconstruction

White

Wood

Martin

et al. 2021

Sensors

View full text Add to dashboard Cite

show abstract

“…22) In the present study, 1.7 MeV photons were generated with a CO 2 laser (Access Laser, LASY-20D), which was the same as that used in our previous experiment for gamma-ray refraction measurement. 23) The experimental parameters are summarized in Table I, and the experimental setup is depicted in Fig. 1.…”

mentioning

confidence: 99%

Reconstruction of the laser Compton scattered gamma-ray distribution in the energy-angle phase space from crystal diffraction data

Hajima¹,

Hayakawa²,

Shizuma³

et al. 2021

Appl. Phys. Express

View full text Add to dashboard Cite

The distribution of laser Compton scattered (LCS) photons in the energy-angle phase space reflects the parameters of the laser and electron beams at the collision point and provides the spectral density and bandwidth available in the LCS source. Diagnosis of the energy-angle phase space is thus crucial for developing high-flux and narrow-bandwidth LCS sources. Such diagnosis has been utilized for photon energies below 100 keV, but not realized for photon energies above 1 MeV. We demonstrated reconstruction of the energy-angle phase space distribution of an LCS photon beam at an energy of 1.7 MeV by utilizing photon diffraction with a silicon mosaic crystal and a silicon comb crystal, both of which have enlarged integrated reflectivity. The reconstructed photon distribution is well reproduced by numerical simulations. The demonstrated diagnostic technique is an efficient tool for the development of LCS photon sources and is beneficial to the use of existing LCS facilities.

show abstract

“…Although we considered a Coulomb gas as the amplifying medium for the light bending, it is conceivable that a similar amplification would occur as well in other mediums, like solid metals of large atomic number such as gold. Such an amplification might be investigated in experiments for precision measurement of refractive index with γ ray [13][14][15], as the Coulombic bending can have a dominating effect on the Delbrück scattering [16].…”

mentioning

confidence: 99%

Bending of light in a Coulomb gas

Lee

2018

Phys. Rev. A

View full text Add to dashboard Cite

Photons traveling in a background electromagnetic field may bend via the vacuum polarization effect with the background field. The bending in a Coulomb field by a heavy nucleus is small even at a large atomic number, rendering it difficult to detect experimentally. As an amplifying mechanism of the effect we consider the bending of light traveling in a chamber of Coulomb gas. The Gaussian nature of the bending in the gas increases the total bending angle in proportion to the square root of the photon travel distance. The enhancement can be orders of magnitude over the bending by a single nucleus at a small impact parameter, which may help experimental observation of the Coulombic bending. * tlee@kunsan.ac.kr

show abstract

Measurement of deflection on germanium and gold prisms using 1.7 MeV laser Compton scattering γ -rays

Cited by 9 publications

References 18 publications

Radioactive Source Localisation via Projective Linear Reconstruction

Radioactive Source Localisation via Projective Linear Reconstruction

Reconstruction of the laser Compton scattered gamma-ray distribution in the energy-angle phase space from crystal diffraction data

Bending of light in a Coulomb gas

Contact Info

Product

Resources

About