A new imaging technology based on Compton X-ray scattering

Abstract

A feasible implementation of a novel X-ray detector for highly energetic X-ray photons with a large solid angle coverage, optimal for the detection of Compton X-ray scattered photons, is described. The device consists of a 20 cm-thick sensitive volume filled with xenon at atmospheric pressure. When the Compton-scattered photons interact with the xenon, the released photoelectrons create clouds of secondary ionization, which are imaged using the electroluminescence produced in a custom-made multi-hole acrylic structure. Photon-by-photon counting can be achieved by processing the resulting image, taken in a continuous readout mode. Based on Geant4 simulations, by considering a realistic detector design and response, it is shown that photon rates up to at least 1011 photons s−1 on-sample (5 µm water-equivalent cell) can be processed, limited by the spatial diffusion of the photoelectrons in the gas. Illustratively, if making use of the Rose criterion and assuming the dose partitioning theorem, it is shown how such a detector would allow obtaining 3D images of 5 µm-size unstained cells in their native environment in about 24 h, with a resolution of 36 nm.

Development of a novel, windowless, amorphous selenium based photodetector for use in liquid noble detectors

“…The application and ubiquity of noble liquid detectors in the fields of high energy physics [1][2][3][4][5][6][7][8], medical imaging [9][10][11][12], and rare event searches [13][14][15][16][17][18][19] is due to the many attractive properties these media provide. Charged particles traversing noble liquids deposit energy in the form of scintillation light and the ionization charge.…”

Dose-efficient Scanning Compton X-ray Microscopy

“…1 (d). Although the highest possible signal would be obtained by measuring scattering over the complete 4π solid angle (or as close to it as possible 9 ), in these measurements we used two pixel-array photon-counting detectors placed close to the sample, above and below the optical axis, capturing scattering angles between 23º and 80º for the upper detector and 5º to 30º for the lower-see Fig. 1 (a).…”

“…Given that the dose to achieve a particular signal to noise ratio in incoherent imaging generally scales with the inverse fourth power of the resolution length 7 and that the tolerable dose increases linearly with the resolution length 1 , we predict a damage-limited resolution of about 5 nm for the pollen grain and diatom, and 8 nm for the bacterium. Achieving a practical implementation of high-resolution scanning Compton X-ray microscopy relies upon the development of effective detectors with large solid angle 9 and the increased brightness of next-generation synchrotron radiation sources 10 . X-rays interact with matter in a variety of ways, and microscopy can be generalised as the localisation of particular interactions by detecting the presence or absence of emanating radiation 11 .…”

Development of a novel, windowless, amorphous selenium based photodetector for use in liquid noble detectors

“…The same procedure described above is used to calculate the peak amplitude, area and the standard deviation. Figures 9,10,and 11 show the results for three different applied fields on the peak amplitude as a function of temperature. These results are summarized in Tables 2, 3, 4 in the appendix.…”

“…The application and ubiquity of noble liquid detectors in the fields of high energy physics [1][2][3][4][5][6][7][8], medical imaging [9][10][11][12], and rare event searches [13][14][15][16][17][18][19] is due to the many attractive properties these media provide. Charged particles traversing noble liquids deposit energy in the form of scintillation light and the ionization charge.…”