Plasma free bubble cavitation in water by a 2.9 {\mu}m laser for bioprinting applications

We investigate the dynamics of the cavitation bubble induced by 2.9 {\mu}m mid-IR laser pulses (10 ns, 10-50 {\mu}J) resulting in a plasma-free direct fast heating of water due to a strong vibrational absorption. We establish a direct correlation between the laser fluence (up to 6 J/cm^2) and the maximum bubble radius (up to 200 {\mu}m). From experimental data, key parameters (threshold energy, internal pressure) can be retrieved by simulations including the water absorption saturation at 2.9 {\mu}m. At a fluence of 6 J/cm^2, we obtain 13 % of the laser energy converted to a bubble energy and we can predict that operating at higher fluence >10 J/cm^2 will lead to a maximum of 20 % conversion efficiency. This results open the door to bioprinting applications using direct absorption of the laser radiation without any additional absorber

Aims and Goals of the Icru and Other International-organizations With Respect To Patient Radiation Protection

After a short historical review, the goals of the ICRU are first presented: definition of quantities and units to be used in the field of ionising radiation, recommendations of measurement procedures for these quantities, definitions of terms and concepts, and investigation and selection of physical parameters. As far as the other international organisations are concerned, some of the main achievements are briefly presented for the IEC, UNSCEAR, ICRP, WHO and IAEA. Besides technical developments and dosimetric intercomparisons, the importance of the education and of the continuous information of the radiologists is stressed. The role played by the CEC in education is recognised in the field of radiation protection in diagnostic radiology