Dynamic Radiation Effects Induced by Short-Pulsed GeV U-Ion Beams in Graphite and h-BN Targets

Figure 6

(a) Measured bending frequency of isotropic SGL R6650 graphite as a function of 1.14 GeV U-ion accumulated fluence. Shaded areas represent the frequencies obtained by ANSYS simulations with pristine properties as well as with 2 and 3 times the pristine Young’s modulus in the beam spot. The uncertainty of the frequencies of 0.02 kHz is obtained by the frequency resolution of the FFT. (b) Relative increase of Young’s modulus as a function of the U-ion fluence measured by microindentation and deduced from simulations of frequency shifts of LDV velocity signals. Error bars represent the error of the mean value for at least 25 microindentation measurements. The uncertainty of the fluence and of Young’s modulus determined from the frequency shift is estimated to be 10% (red dashed lines). The shaded blue area represents the ratio of Young’s modulus of the glassy carbon grade HTW SIGRADUR K [31] and SIGRAFINE R6650 [21] taken from the respective data sheets.

(a)

(b)