Amu project - a observar muoes
This project intends to design, build and test a portable cosmic ray muon detector for muon flux measurements.
Such measurements should show that the muon fluxes depend on the zenith angle, on air pressure and on muon absorption prior
to its detection. Additionally, the muon decay time could also be measured with such a scintilator setup.
The detector design is not yet fixed but inspired by other projects (CosMO project is one of them) could be made of a set of
three small scintillators (20*25 cm) whose light could be colected by optical fibers WLS and photons detected by multi-pixel
photon counters (MPPC). Other possibility would be to have a simple light colector (aluminium foil at the end of the scintillator
carrying the light to the MPPC.
In order to optimize the design of the single scintillator element, its simulation shall be made either using
the LRCsim package developed within Lab of Cosmic Rays or the CERN Geant4 package.
Finally, the test of the scintillator element is crucial to establish the signal threshold at which it will be operated.
The larger it will be the signal and therefore the working signal threshold, the less important it will be the dark counts noise.
For instance, the dark counts rate ranges from 10^2 to 10^4 /sec for 1.5 pe threshold, depending on the applied voltage.
Project status (20 June 2014)
- First test of one of the modules seem to have good results (see photos)
- scintillator plates were were cutted and polished, grooves for fibers made in LIP Coimbra workshop
- the 9 fibers were glued to the scintillators
- the wood frames where the scintillators will be mounted were also assembled
- fibers cutted and polished with white paper
- one scintillator wrapped with Tyvek and the fibers mounted on support
- DC/DC converter from ISEG received
- Hamamatsu MPPC ordered and received
- optical cement from Saint Gobain: quotation asked; some cement recovered and used to glue fibers to scintillators
- Scintillator setup simulation on going (some results soon)
- electronics: analog and digital (on going)
- boxes (design)
- telescope mechanical structrure (design)
assembling photos (June 2014)
First tests (20 June 2014)
1st module assembled
scintillator with the visible grooves for fibers; gluing fibers
waiting for fiber/scintillator gluing (24hr)
wrapping the scintillator with Tyvek (diffusive layers)
optical photons readout: wls fibers
The WLS fibers being used are the ones from Kuraray that were also used in the Atlas experiment (green fibers): Y-11(200)
- double cladding
- 1mm diameter
- absorption length (probability to absorb photon): 0.1mm for all wavelengths
- refractive indexes:
- core (polystyrene): n = 1.59, rho=1.05 g/cm2
- inner cladding (polymethylmethacrylate): n=1.49, rho=1.19 g/cm2
- outer cladding (fluorinated polymer): n=1.42, rho=1.43 g/cm2
General Doc Links
- plastic scintillator EJ-200
- optical fibers
- silicon counting photodetectors (MPPC)
- DC-DC converter: iseg APN 02 255 5
- data acquisition card acq card