Recently, the media released a laser treatment of tumor research results. Specifically, the theory of the use of the collisionless shock wave acceleration mechanism can produce this high-quality high-energy proton beam theory, through the existing laser conditions in the proton energy calibration to 100 megahertz electron volts, to meet the burning laser proton knife treatment Kill tumor cell requirements.
It is reported that in the study, the researchers use the circular polarization film super-short laser pulse bombardment nano-thickness film target, obtained a large flow strong, quasi-single high-quality proton beam, proton energy peak energy to 9MeV, peak flow up to 3 × 1012 protons / MeV / sr, can kill tumor cells and protect healthy cells of laser proton beam.
In fact, the high-energy proton beam in the material transmission has a unique Bragg peak, simply is the proton in the transmission process of loss of energy is generally very small, after a transmission distance, the proton beam most of the energy deposited mainly at the end. Therefore, this property is useful in the treatment of cancer in the body, the effective use of high energy at the end to kill cancer cells while well protecting healthy cells. In fact, based on the traditional accelerator proton knife tumor treatment at home and abroad have made great progress. Because the cost is very difficult to spread. This time, the circular polarization of the ultra-short high power laser pointer drive to accelerate the formation of high-quality proton beam, because of its acceleration gradient (unit length of particles obtained energy) is much larger than the traditional accelerator, greatly reducing the scale of the accelerator, which is expected to reduce the cost of treatment, become The new generation of treatment for cancer proton scalpels, the results of this study also represents a laser-driven proton knife program has taken a key step forward.
Laser marking technology to lead enterprises to enter the laser processing industry, especially fiber laser in laser equipment widely used, the laser marking industry has reached the market ‘peak’, but the laser marking application for many years, we see the common laser hit Patterns are black and white. On the current laser marking process, can only use part of the fiber laser in the stainless steel above the color mark.
The main factors of fiber laser marking machine are divided into internal factors and processing of two factors. Internal factors mainly for the laser frequency, green laser light beam mode and beam divergence angle, laser power, reasonable optical shaping with the processing of auxiliary gas substances. Internal factors mainly in the early models when the allocation of attention, should follow the advice of laser engineers to buy. Another factor mainly requires customers to pay attention to the processing, mainly for the marking density, marking the format, marking the depth and laser spot size.
When the laser is marked with a stainless steel, the color change of the surface layer of the material can be changed by adjusting the laser beam to obtain a decorative effect of different colors. The advantage is that its pulse width and frequency are independently adjustable, adjust one of them does not affect the other laser parameters, which is Q-switched structure of the laser does not have. And this feature, to the stainless steel color marking with unlimited possibilities. In the actual marking operation, pulse width, frequency, power, speed, fill the way, fill the pitch, delay parameters and so on these factors will affect the color effect.
It is understood that this ultra-short laser drive generated by the ultra-short pulse, high-quality high-energy proton beam can also be applied to proton photographic and material testing, red laser nuclear fusion fast ignition, laboratory astrophysics, laser nuclear physics and nuclear medicine aspects of the study.