My master thesis revolves around the Silicon Carbide Detector (SiC), which is a new concept of a solid crystalline detector, hopefully well suited to the fusion-like environments. The aim is to use it as an alpha detector; as such, the need is to test it for all other type of particles (expecially neutrons) which will make up the common background of the signal from the alphas. So: how to test it for neutrons of every energy?
Neutron source N_TOF at CERN has the neutrons we’re looking for
N_TOF is a pulsed neutron source, with a long travel distance between the generation of neutrons and the detectors. Being as it is, it is possible to infer the energy of every incoming neutron from the delay between the start of the pulse and the time of its arrival. So, I could characterize the response of the detector to neutrons at a well known energy for every energy (in a range between 0,5 and 100 MeV). When we were agreed two months of beam time at N_TOF at CERN, we seized the opportunity.
Experimental physics: from the assembly work to the results analysis
I set off from Milano with the team coordinated by Dr. Tardocchi. We arranged a small car convoy to move to CERN and set up the SiC detector and electronic – along with two diamond detectors whose well-known behaviour would be used as a comparison. I had been presented to Dr. Murtas, who would have been my supervisor at CERN, a couple of days before our start. After I took part in the installation of the detectors, I was addressed with the task of following their maintenance and the analisys of their output, building ex-novo an appropriate program, discussing the results to both my supervisor at home and at CERN and making appropriate changes to the experimental apparatus.
After a week of test and optimization I was able to collect and analyze the first data. The first launch of my program routine highlighted the presence of many neutron energy over collected energy patterns, result of the same neutron-on-nucleus reaction at different neutron energies. It was my hope to find such a thing. Those patterns matched quite well both with simulation data and previous tests conducted in other facilities. I kept improving the program, implementing methos to discard pile-up effects, noise and background; I was also able to identify peaks in the efficiency of the detector, and comparing it to the elastic and anelastic cross-sections. I was helped by the data collected by an other, pixelated detector on the same line, courtesy of my supervisor at CERN, whose data made me possible to characterize the shape of the beam and further improving the quality of my aquisition.
My personal experience at CERN
This experience has been my first, big experience in a large physics lab. It was extremely stimulant, in a very professional way. I had the chance to put to test my computing skills in C++ and Python, and it got me accostumed to the rhytms and customs to professional experimental physics. For the first time I also had the chance to follow an entire project, from the setting up of the mechanical and electronical apparatus to the discussion of results and simulation, which is still ongoing. I feel very formed by this 2-month long experience and I have to thank greatly the economic support from FuseNet which made it possible.
- Matteo Hakeem Kushoro