A prototype solar particle detector has been developed by researchers at the Institute of Physics and Technology of Moscow (MIPT).
The system can detect protons with kinetic energies of between 10 and 100 megaelectronvolts and 1-10 MeV electrons.
This includes much of the Sun’s emanating high-energy particle flux.
The new detector will enhance the safety of astronauts and spacecraft against radiation and also advance our knowledge of solar flares.
The research findings are published in the Instrumentation Journal.
In the active regions of the Sun’s atmosphere, when energy is transferred from one form to another, streams of particles – or cosmic rays – with energies of approximately 0.01-1,000 MeV are formed. Electrons and protons are the bulk of these particles, but nuclei from helium to iron are also detected, albeit in much smaller amounts.
The current opinion is that there are two main elements in the particle flux.
First, in short flares, there are narrow streams of electrons which last from ten minutes to several hours.
And then there are large shock wave flares that last up to several days and contain mainly protons, with some heavier nuclei occasionally.
Some fundamental issues remain unanswered despite the huge quantities of data generated by solar orbiters. The exact mechanisms behind particle acceleration in the shorter and longer solar flares are not yet understood by scientists.
It is also unclear what role magnetic reconnection plays for particles as they are accelerated and leave the solar corona, or how and where before they are accelerated on impact waves, the initial particle populations are created.
Researchers need particle detectors of a new kind to address these questions, which would also underlie new spacecraft safety protocols that would detect the initial electron wave as an early warning of the imminent danger of proton radiation.
On the design of a prototype high-energy particle detector, a recent research by a team of physicists from MIPT and other institutes studies.
The system consists of multiple photodetector-connected polystyrene disks.
It loses some of its kinetic energy as a particle moves through the polystyrene and releases light that is recorded as a signal for subsequent computer analysis by a silicon photodetector.
Alexander Nozik of the Methods Laboratory for Nuclear Physics at MIPT, the project’s chief, said, “The concept of plastic scintillation detectors is not new, and in Earth-based experiments such devices are ubiquitous.”
The use of a segmented detector along with our own mathematical reconstruction methods is what allowed the remarkable results we obtained.
Part of the paper deals with optimizing the geometry of the detector section in the Journal of Instrumentation.
The problem is that while larger disks mean that at any given moment more particles can be studied, it comes at the cost of the weight of the instrument, making it more costly to send to orbit.
Furthermore, the disk’s resolution decreases as the diameter increases.
Thinner disks calculate proton and electron energies in terms of thickness with greater accuracy, but more photodetectors and larger electronics are also needed for a large number of thin disks.
To refine the parameters of the device, the team relied on computer modeling and eventually designed a prototype small enough to be launched into space.
The cylindrical device has a diameter of 3 centimeters and a height of 8 centimeters.
The detector consists of 20 separate polystyrene disks, offering an appropriate precision of more than 5 percent.
The sensor has two modes of operation: it tracks individual particles in a flux which does not exceed 100,000 particles per second, and when the radiation is more intense, it switches to an integrated mode.
The second mode uses a special technique that does not require much computational power to analyze particle distribution data developed by the authors of the analysis.
“Our device has performed very well in laboratory tests,” says study co-author Egor Stadnichuk of the MIPT Nuclear Physics Methods Laboratory. The next step is to create new electronics which would be necessary for the application of the space detector.
We will also adjust the detector’s configuration to the spacecraft’s constraints.
This implies that we are going to make the unit smaller and lighter and add side shielding.
Furthermore, we intend to add a f