This page gives a brief overview of the project, giving an indication of the main solutions explored.
- Summary: Building on the successful achievements obtained with the former project Mu-blast, BLEMAB proposal investigates the imaging capability of the inner zone of the blast furnaces using a muon absorption detector that is able to realize a sort of blast furnace radiography. In parallel to this measurement a new enhanced multipoint probe (eMPVP), capable of measuring the gas temperature inside the blast furnace along its whole working height, is also tested. Furthermore, two different BF models will be also developed to support the analysis of results obtained from the measurement systems.
- Objective: It is expected that the new muon technique gives a major contribution to the on-line control of the blast furnace process, especially as it should allow direct detection of the position of the cohesive zone of the blast furnace which would be of great help to the process control. The shape of the cohesive zone is quite important for efficient blast furnace (BF) operation. Without a proper shape the softening material would just block the gas flow and give rise to highly erratic and inefficient operation. To charge the coke as horizontal layers and give the cohesive zone a bell like shape the coke layers are at an angle to the cohesive zone and the gas flow can be controlled even within the cohesive zone. Current state of the art is to adjust the shape of the cohesive zone by some control actions changing the coke to ore ratio and distribution at the charging, and to rely on experience.
- Method: The method proposed in the present research is the radiographic imaging exploiting cosmic ray muons, the so-called muon radiography, sometimes referred to as “muography”. Several partners are involved in this field since many years, with projects ranging from volcanology to archaeology, civil engineering, remediation of nuclear waste storage sites etc. This technique is different from the muons imaging technique, based on muons scattering tomography, investigated in the previous MUBLAST project.
Radiography of massive structures by muon transmission
The basic idea is to start from the experimental knowledge of the muon spectrum at ground level. Apart from the effect due to the influence of the Earth magnetic field on positive and negative muons, that introduce a small asymmetry on the azimuth angle (), called the East-West effect, the muon flux at ground level (f) has important dependencies on particle momentum (p) and zenith angle (θ).
The group INFN-UNIFI has measured f(p,θ) for momentum in the range 0.1-130 GeV/c and zenith angle from 0 up to 80 using the ADAMO detector, a magnetic spectrometer made of a permanent magnet and a micro-strip silicon tracker, with a Maximum Detectable Rigidity of approximately 250 GeV/c. Based on this measurement a Ground Level Muon Generator (GLMG) has been developed and it is currently used as a stand-alone software.
Muon radiography is based on the measurement of muon transmission, the fraction of muons that is able to cross the material thickness encountered along a selected direction of angles.
The transmission can be estimated experimentally comparing the muon flux measured in front of the target under study with the flux measured at free sky in the same direction. The comparison of the measured transmission with simulations taking into account the geometry of the structure under study allows reconstructing the average angular density distribution of the target.
One purpose of the proposal is the final development of a new tomographic algorithm based on muon transmission data and its test on simulated and real data sets. This software can be developed in a completely custom way or combining custom routines with software packages used for the simulation of particle interactions.