Figure 6
From: Enhancement of the ionoacoustic effect through ultrasound and photoacoustic contrast agents
Simulated photo-enhanced ionoacoustic signal from clinical proton beams in tumor and liver tissue. (a) Energy deposition of the optical photons obtained from Fluka2021.1beta, the hatch area represents the liver. Ionoacoustic signals obtained from synchro-cyclotron (\({2.5}{\,\upmu \hbox {s}}\) Gaussian pulse) without CA (black) or with CA and photoacoustic pressure corresponding to a light yield of \({5\times 10^{4}}\) photons/MeV (blue) and \({1\times 10^{5}}\) photons/MeV in (b) time and (c) frequency-___domain. Ionoacoustic signals obtained from synchrotron (50 ms burst with a MHz micro-structure) without CA (black) or with CA and photoacoustic pressure corresponding to a light yield of \({5\times 10^{4}}\) photons/MeV (blue) and \({1\times 10^{5}}\) photons/MeV in (d) time and (e) frequency-___domain. (f) Fourier transform of the filtered spectra show in (e), depicting the distance from the Bragg peak to the entrance of the tumor, assuming a speed-of-sound of \({1556.9}{\,\hbox {ms}^{-1}}\).
