AMU project - observing muons: simulation
A prototype of a portable muon telescope was built along March to July of 2014 for muon flux measurements.
Muons are continuously produced on proton-air interactions being carried down with a bunch of other charged and neutral particles
in the so-called, air shower.
The work proposed here is to simulate within the LRCsim ROOT based framework (developed within the Lab RC) the telescope setup,
operate it and compare the real data with simulations.
Muon rate measurements should show that the muon fluxes depend on the zenith angle, on air pressure and on muon absorption prior
to its detection.
The detector AMU is composed of three scintilators of 20X20 cm coupled to nine wavelength shifter optical fibers (WLS) and
multi proportional photoelectron counters (MPPC).
The three scintilators will be superimposed in order to make a muon telescope.
The work to be developed on this semester is the AMU simulation that will be used for estimating the magnitude
of the signal that will be observed.
The working steps of the simulation work are the following:
- 0. define the detector geometry: a box of 20 x 20 x 1 cm made of plastic scintilator material, air around and Tyvek
- 1. Generation and propagation of the incident muons
- 2. Calculate the mean energy loss (dE/dX) through the Bethe-Bloch formula and fluctuate its value using a gaussian or a Landau distribution
- 3. Generate photons in scintillator
- 4. Propagate photons in scintillator using reflection/refraction laws and considering attenuation losses and losses due to surface imperfections
- 5. Handle the capture, trapping and propagation of photons in the WLS fiber (considere fiber attenuation losses)
- 6. Convolution of SiPM response (detection efficiency)
Lectures notes (F Barao, 2015-16)
status (Feb 2016)
- scintillator plates were were cutted and polished, grooves for fibers made in LIP Coimbra workshop
- DC/DC converter received
- Hamamatsu MPPC ordered and received
- optical cement from Saint Gobain: quotation asked
- Scintillator geant4 setup simulation
- electronics: front-end electronics designed and being teste
- HV alim (70V): a beaglebone shield designed and assembled to control HV and colect front-end signals
- boxes (design)
- telescope mechanical structure (design)
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
- diameter: 1mm
- 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
plastic scintilator: EJ-200
The idea is to develop electronics able to:
- power supply providing +5V, -5V and ground
- power up the light detector (silicon PM) through the ISEG DC/DC converter
- front-end electronics that will receive the signal from the silicon
PM, do its amplification and discrimination
- digital electronics FPGA based to handle the signal coincidences and signal
- computer station to run a simple acquisition system working as DAQ
server (ethernet, wireles, etc connections)
Related Electronics biblio
We intend to use the beaglebone board as acquisition server and event builder. After some discussion with Renaud Gaglione (LAPP) it seems that the signals from the Front-End electronics could be converted (TTL-CMOS) and a AND gate used to produce a signal to be gathered by GPIO. This implies to develop a beagleborad plugin board...
power: a power transformer and the DC/DC converter (Nov, 2014)
AMU Project bibliography
- optical fibers
- silicon counting photodetectors (MPPC)
- DC-DC converter: iseg APN 02 255 5
- data acquisition card acq card
- COSMO project