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Step by step simulation of phototubes for the KM3NeT and ANTARES optical modules
Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
Contents lists available at ScienceDirect
Nuclear Instruments and Methods in Physics Research A journal homepage: www.elsevier.com/locate/nima
Step by step simulation of phototubes for the KM3NeT and ANTARES optical modules Christophe M.F. Hugon INFN Sezione di Genova, Italy
on behalf of the ANTARES and KM3NeT collaborations art ic l e i nf o
Keywords: Neutrino telescopes Simulation GEANT4 Phototubes
a b s t r a c t This proceeding presents the step by step simulation of the ANTARES neutrino telescope and KM3NeT-it prototype optical modules. After a description of the physics goals and both the detectors, the aim of a detailed simulation of the optical module will be presented. The main results will be shown, together with its perspectives. & 2014 Elsevier B.V. All rights reserved.
1. The neutrino telescopes ANTARES and the KM3NeT-it prototype
Capo-Passero. Both of them are located in the Mediterranean Sea, which allows them to aim to the galactic sources.
Among the information vectors to explore the sky, the neutrino is a very interesting candidate, due to its properties. Indeed its very low cross-section allows it to emerge from dense media and to travel through very long distances. In addition it cannot be deflected by magnetic fields thanks to its null charge. High energy neutrinos (4 TeV) are expected to be emitted by a large range of astrophysical objects such as supernovae and GRB. In addition, the observation of neutrinos could also reveal unexpected sources or processes. The main challenge for the neutrino detection and the reconstruction of its origin is the weakness of the neutrino interaction. Therefore neutrino telescopes require a very large effective volume of a transparent volume such as water or ice. Thanks to an array of photodetectors the Cherenkov light emitted by the charged lepton (produced by electroweak interaction between the neutrino and the matter) can be detected. The reconstruction of the light cone associated to the muon track allows us to deduce the origin of the incoming neutrino.1 The detection and reconstruction of this cone by the photo-detectors (thanks to the timing and the positions and number of the detected photons, or hits) determines the origin of the parent neutrino and an estimation of its energy. The earth represents a screen to charged secondary atmospheric particles, so the detectors are installed in deep depth (to limit the down-going background) and are optimized to measure the up-going muons. Indeed the Optical Modules (OM) are oriented downwards. This section will describe the ANTARES neutrino telescope [1], and the prototype detector KM3NeT-it [2], deployed in
1.1. ANTARES
1 Although the muon is the most efficient channel, the light produced by electrons and τ can be detected.
ANTARES is currently the largest deep-sea neutrino telescope in the Northern Hemisphere. It is situated 40 km off the French coast, and was deployed at about 2500 m depth in the Mediterranean Sea in 2008 at its full configuration. The apparatus is made up of 12 lines of 450 m high. These lines are separated by a space from 60 to 75 m. Each line supports 25 storeys of Optical Modules (OMs) triplet. The OMs contain 10 in. Hamamatsu R7081-20 Photo-Multiplier tubes (PMTs), enclosed in 17 in. pressure-proof glass spheres and are oriented 451 downward (Fig. 1). The contact between the glass sphere and the PMt is done thanks to an optical gel. The detector contains a total number of 885 OMs for a fiducial volume of about 0.02 km3. The time calibration is performed by means of an in situ array of laser and LED beacons. 1.2. KM3NeT-it prototype The KM3NeT-it detector prototype, also known as the project NEMO, was deployed in March 2013 to validate a deep site suitable for a km3 scale detector and data have been taken until Summer 2014. The site is located at 100 km off the Sicilian coast, near CapoPassero, at 3500 m depth. The prototype apparatus consists of a semi-rigid structure composed of 8 floors, which are metal bars 8 m long, vertically spaced 40 m from each other and orthogonally oriented with respect to their vertical neighbors. Each extremity of the bars support two OMs containing the same 10 in. PMt as
http://dx.doi.org/10.1016/j.nima.2014.11.098 0168-9002/& 2014 Elsevier B.V. All rights reserved.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
2
C.M.F. Hugon / Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
the vessel, mainly composed by the pressure proof glass and
the optical gel and a support cap for KM3NeT-it. This part is passive, the material properties are the only input, the PMt. Its geometry is more complex, and the physics used for the photo-detection is based on a simulation of the photocathode [5], described in Section 3.2.
It is important to note that in the case of KM3NeT-it the bar structure has been implemented for the angular acceptance simulation in order to take into account the shadowing effects. These structure materials are considered to absorb the light completely. Fig. 1. Schematic 3D view of the ANTARES optical module and its components [3]. The KM3NeT-it OM difference is only the glass sphere of 13 in.
ANTARES enclosed in 13 in. pressure-proof glass spheres. The contact between the glass sphere and the PMts is done using the same gel as ANTARES. The OMs are maintained on the bar thanks to a cap, one is oriented horizontally, pointing outside, and the other one is oriented vertically, pointing downwards.
2. Goal of a detailed OM simulation In order to understand the detected events from the neutrino telescope ANTARES and the KM3Net-it prototype, a precise simulation is essential. Indeed the separation between the signal and the background noise and the efficiency estimations can be done thanks to Monte Carlo simulation. This Monte Carlo considers the incoming atmospheric neutrino and muon fluxes, the medium and the structure of the detector, including the efficiency of the detection units (the OM). The step by step simulation is the simulation of the propagation of each photon, from the Cherenkov effect or other sources, including their different interactions in the matter. After the simulation of numerous events, we can obtain mean effects such as the detection probability and the water properties. This information can be tabulated and used for final simulations (km3net [4]) to offer a consensus between the simulation quality and the calculation time. The goal is to provide the following two basics elements:
the OM detection efficiency as a function of the angle and the wavelength of the incident photon (angular acceptance),
the water properties such as the absorption length and the scattering length on molecule and on macroscopic particles. Indeed, even if some water properties such as the salinity or the index are considered as a fixed input, the confrontation between the simulation and the experimental data complete the information about the absorption and the scattering properties. These results are then tabulated and used as inputs for the full detector simulation km3net. Two physical inputs were used to calibrate and test the step by step simulation:
3.1. The photo-multiplier tube geometry and the photocathode The considered basic geometrical components are represented in Fig. 2. In order to simplify the geometry description, the different PMt basic components are calculated as a function of the following few parameters:
the PMt radius, the height of the photocathode spherical component, the height and small radius of the photocathode elliptic component,
the height of the reflective glass elliptic component, the height and maximum radius of the reflective glass conic component,
the height and radius of the reflective glass tube component.
3.2. The photocathode simulation The properties of the PMt photocathode have been experimentally measured [5] in the visible range in order to investigate its different parameters such as its absolute reflectance at near-normal incidence, the polarization dependent reflectance at various angles, and the change of polarization after the reflectances. These experimental inputs were combined with a theoretical model [5] to predict the fraction of incident photons that is reflected, transmitted or absorbed, as a function of the angle, the wavelength and the properties of the on-contact middle (optical gel). The code used by the simulation was adapted from the Double Chooz GEANT4 public simulation [6] This part provides the probability of a conversion of the incident photon to an electron (photo-electron). There are two important elements to simulate, both as a function of the incident angles:
the probability to get a signal from the photo-electron, the photocathode flaws (thickness irregularity, density, etc.). Those last elements are unique for any PMt, and has been calibrated thanks to experimental measurements in laboratory (Section 4.3) and in situ measurements (Section 4.2).
the relative efficiency measurement of the OMs as a function of the impact position on the OM sphere surface,
the in situ natural 40K decay rate measured by the OMs.
3. Geometry, materials and photocathode simulation Fig. 1 represents the full optical module for the both configurations. It is composed by the following:
Fig. 2. Representation of a simulated R7081-20 PMt and its different geometric components.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
C.M.F. Hugon / Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
3
3.3. The full OMs geometries As described in Sections 1.1 and 1.2, the PMt is inside a glass sphere. In the case of KM3NeT-it, the OM is contained in a cap which supports it on the bar structure. As shown in Fig. 3, only these component are used for the 40K decay analysis. For the angular acceptance simulation of KM3NeT-it the bar structure is also included. The other parts of the detectors (cables, structures, etc.) are neglected.
4. Calibration and results 4.1. Relative calibration In order to have a relative efficiency input as a function of the angle, a setup was developed at the ECAP (Erlangen) then at the APC (Paris) [7,8]. For this purpose, in a black box, a motorized wellknown light source moves around the tested OM, with its collimated beam oriented on a quasi-normal angle to the OM surface. This method allows us to measure the effective relative efficiency of the full OM. Three different OMs were tested on 3 different scanning angles. Fig. 4 shows the simulation calibrated on the mean of these 9 measurements, taking in account the standard deviation degree by degree. 4.2. The absolute calibration To measure the absolute efficiency, one can use the well-known K natural decay in the sea water. The coincidences between two close OMs were used to exclude the background noise. Both the configurations, ANTARES and KM3NeT-it, allow us to do a cross check on the total activity. The best fit on both detectors gives the results of Table 1. It is important to note that those results are compatible with the laboratory measurements given in [8].
40
4.3. The angular acceptance The angular acceptance of the OMs is one of the main purpose of this work. In order to get a consensus between the simulation accuracy and the calculation time, the step by step simulation provides a tabulated efficiency of the OMs for the global simulation km3net. This table contains the efficiency for a beam of
Fig. 4. Relative results of the calibration based on the laboratory scan results. The blue points are the experimental means of all the measurements, their errors correspond to the standard deviation, degree by degree, of the corresponding mean points. The black line represents the mean given by the simulation, the green and the red lines represent the predicted standard deviation by the simulation. The efficiency depression at 01 correspond to the central node of the μ-metal grid and the OM glass and photocathode flaws (thickness). The same effect, at lower scale, can be observed at 201. The bump at 551 corresponds to the reflection on the gel/air interface. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)
Table 1 Mean of the 40K coincidence rate between each couple of OM of ANTARES and KM3NeT-it from the data analysis (experimental) and the step by step simulation (simulation). Experiment
ANTARES
KM3NeT-it
Experimental (Hz) Simulated (Hz)
16 15.3
21 21.6
parallel photons hitting the OM at a specific angle (with a beam radius equal to the OM radius).
5. Conclusion and perspectives Thanks to the last improvements of the simulation, such as the wavelength dependency, the geometry refinement and the relative and absolute calibration, the angular acceptance is more accurate, therefore the general simulation km3net is more precise and the efficiency better understood. After the calibrations, the maximal angular acceptance (at 01) correspond to the one measured in laboratory, and the predicted 40K decay rates correspond to the measured ones in the both configurations, which validate the simulation. One of the main perspectives for this step by step simulation is to measure the water properties of the KM3NeT-it site thanks to the LED calibration system. As a function of the different wavelengths and the different distances (from the 4 LED, each one at a different floor) the total absorption and the arrival time due to the scattering of the light in the water. References
Fig. 3. Illustration of the step by step simulation for the ANTARES and KM3NeT-it configurations. Both detectors are simulated in the same water volume, back to back, for the 40K decays (top, Section 4.2). The KM3NeT-it detector prototype is simulated with the bar structures for the angular acceptance (bottom, Section 4.3).
[1] V.V. Elewyck, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 742 (0) (2014) 63. [2] C.A. Nicolau, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 742 (0) (2014) 203. [3] A. Coll, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 484 (13) (2002) 369. [4] C. James, Internal Note: km3net Release.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
4
C.M.F. Hugon / Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
[5] D. Motta, S. Schnert, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 539 (12) (2005) 217. [6] D. Motta, Glg4 Simulation. URL 〈http://neutrino.phys.ksu.edu/MAND-sim/MAN D-sim%20talks/DoubleChooz_motta.pdf 〉.
[7] C. Alexandre, Internal Note: Black Box Set-Up on the ANTARES OM. [8] A. Creusot, et al., Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 725 (0) (2013) 144.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
Contents lists available at ScienceDirect
Nuclear Instruments and Methods in Physics Research A journal homepage: www.elsevier.com/locate/nima
Step by step simulation of phototubes for the KM3NeT and ANTARES optical modules Christophe M.F. Hugon INFN Sezione di Genova, Italy
on behalf of the ANTARES and KM3NeT collaborations art ic l e i nf o
Keywords: Neutrino telescopes Simulation GEANT4 Phototubes
a b s t r a c t This proceeding presents the step by step simulation of the ANTARES neutrino telescope and KM3NeT-it prototype optical modules. After a description of the physics goals and both the detectors, the aim of a detailed simulation of the optical module will be presented. The main results will be shown, together with its perspectives. & 2014 Elsevier B.V. All rights reserved.
1. The neutrino telescopes ANTARES and the KM3NeT-it prototype
Capo-Passero. Both of them are located in the Mediterranean Sea, which allows them to aim to the galactic sources.
Among the information vectors to explore the sky, the neutrino is a very interesting candidate, due to its properties. Indeed its very low cross-section allows it to emerge from dense media and to travel through very long distances. In addition it cannot be deflected by magnetic fields thanks to its null charge. High energy neutrinos (4 TeV) are expected to be emitted by a large range of astrophysical objects such as supernovae and GRB. In addition, the observation of neutrinos could also reveal unexpected sources or processes. The main challenge for the neutrino detection and the reconstruction of its origin is the weakness of the neutrino interaction. Therefore neutrino telescopes require a very large effective volume of a transparent volume such as water or ice. Thanks to an array of photodetectors the Cherenkov light emitted by the charged lepton (produced by electroweak interaction between the neutrino and the matter) can be detected. The reconstruction of the light cone associated to the muon track allows us to deduce the origin of the incoming neutrino.1 The detection and reconstruction of this cone by the photo-detectors (thanks to the timing and the positions and number of the detected photons, or hits) determines the origin of the parent neutrino and an estimation of its energy. The earth represents a screen to charged secondary atmospheric particles, so the detectors are installed in deep depth (to limit the down-going background) and are optimized to measure the up-going muons. Indeed the Optical Modules (OM) are oriented downwards. This section will describe the ANTARES neutrino telescope [1], and the prototype detector KM3NeT-it [2], deployed in
1.1. ANTARES
1 Although the muon is the most efficient channel, the light produced by electrons and τ can be detected.
ANTARES is currently the largest deep-sea neutrino telescope in the Northern Hemisphere. It is situated 40 km off the French coast, and was deployed at about 2500 m depth in the Mediterranean Sea in 2008 at its full configuration. The apparatus is made up of 12 lines of 450 m high. These lines are separated by a space from 60 to 75 m. Each line supports 25 storeys of Optical Modules (OMs) triplet. The OMs contain 10 in. Hamamatsu R7081-20 Photo-Multiplier tubes (PMTs), enclosed in 17 in. pressure-proof glass spheres and are oriented 451 downward (Fig. 1). The contact between the glass sphere and the PMt is done thanks to an optical gel. The detector contains a total number of 885 OMs for a fiducial volume of about 0.02 km3. The time calibration is performed by means of an in situ array of laser and LED beacons. 1.2. KM3NeT-it prototype The KM3NeT-it detector prototype, also known as the project NEMO, was deployed in March 2013 to validate a deep site suitable for a km3 scale detector and data have been taken until Summer 2014. The site is located at 100 km off the Sicilian coast, near CapoPassero, at 3500 m depth. The prototype apparatus consists of a semi-rigid structure composed of 8 floors, which are metal bars 8 m long, vertically spaced 40 m from each other and orthogonally oriented with respect to their vertical neighbors. Each extremity of the bars support two OMs containing the same 10 in. PMt as
http://dx.doi.org/10.1016/j.nima.2014.11.098 0168-9002/& 2014 Elsevier B.V. All rights reserved.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
2
C.M.F. Hugon / Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
the vessel, mainly composed by the pressure proof glass and
the optical gel and a support cap for KM3NeT-it. This part is passive, the material properties are the only input, the PMt. Its geometry is more complex, and the physics used for the photo-detection is based on a simulation of the photocathode [5], described in Section 3.2.
It is important to note that in the case of KM3NeT-it the bar structure has been implemented for the angular acceptance simulation in order to take into account the shadowing effects. These structure materials are considered to absorb the light completely. Fig. 1. Schematic 3D view of the ANTARES optical module and its components [3]. The KM3NeT-it OM difference is only the glass sphere of 13 in.
ANTARES enclosed in 13 in. pressure-proof glass spheres. The contact between the glass sphere and the PMts is done using the same gel as ANTARES. The OMs are maintained on the bar thanks to a cap, one is oriented horizontally, pointing outside, and the other one is oriented vertically, pointing downwards.
2. Goal of a detailed OM simulation In order to understand the detected events from the neutrino telescope ANTARES and the KM3Net-it prototype, a precise simulation is essential. Indeed the separation between the signal and the background noise and the efficiency estimations can be done thanks to Monte Carlo simulation. This Monte Carlo considers the incoming atmospheric neutrino and muon fluxes, the medium and the structure of the detector, including the efficiency of the detection units (the OM). The step by step simulation is the simulation of the propagation of each photon, from the Cherenkov effect or other sources, including their different interactions in the matter. After the simulation of numerous events, we can obtain mean effects such as the detection probability and the water properties. This information can be tabulated and used for final simulations (km3net [4]) to offer a consensus between the simulation quality and the calculation time. The goal is to provide the following two basics elements:
the OM detection efficiency as a function of the angle and the wavelength of the incident photon (angular acceptance),
the water properties such as the absorption length and the scattering length on molecule and on macroscopic particles. Indeed, even if some water properties such as the salinity or the index are considered as a fixed input, the confrontation between the simulation and the experimental data complete the information about the absorption and the scattering properties. These results are then tabulated and used as inputs for the full detector simulation km3net. Two physical inputs were used to calibrate and test the step by step simulation:
3.1. The photo-multiplier tube geometry and the photocathode The considered basic geometrical components are represented in Fig. 2. In order to simplify the geometry description, the different PMt basic components are calculated as a function of the following few parameters:
the PMt radius, the height of the photocathode spherical component, the height and small radius of the photocathode elliptic component,
the height of the reflective glass elliptic component, the height and maximum radius of the reflective glass conic component,
the height and radius of the reflective glass tube component.
3.2. The photocathode simulation The properties of the PMt photocathode have been experimentally measured [5] in the visible range in order to investigate its different parameters such as its absolute reflectance at near-normal incidence, the polarization dependent reflectance at various angles, and the change of polarization after the reflectances. These experimental inputs were combined with a theoretical model [5] to predict the fraction of incident photons that is reflected, transmitted or absorbed, as a function of the angle, the wavelength and the properties of the on-contact middle (optical gel). The code used by the simulation was adapted from the Double Chooz GEANT4 public simulation [6] This part provides the probability of a conversion of the incident photon to an electron (photo-electron). There are two important elements to simulate, both as a function of the incident angles:
the probability to get a signal from the photo-electron, the photocathode flaws (thickness irregularity, density, etc.). Those last elements are unique for any PMt, and has been calibrated thanks to experimental measurements in laboratory (Section 4.3) and in situ measurements (Section 4.2).
the relative efficiency measurement of the OMs as a function of the impact position on the OM sphere surface,
the in situ natural 40K decay rate measured by the OMs.
3. Geometry, materials and photocathode simulation Fig. 1 represents the full optical module for the both configurations. It is composed by the following:
Fig. 2. Representation of a simulated R7081-20 PMt and its different geometric components.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
C.M.F. Hugon / Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
3
3.3. The full OMs geometries As described in Sections 1.1 and 1.2, the PMt is inside a glass sphere. In the case of KM3NeT-it, the OM is contained in a cap which supports it on the bar structure. As shown in Fig. 3, only these component are used for the 40K decay analysis. For the angular acceptance simulation of KM3NeT-it the bar structure is also included. The other parts of the detectors (cables, structures, etc.) are neglected.
4. Calibration and results 4.1. Relative calibration In order to have a relative efficiency input as a function of the angle, a setup was developed at the ECAP (Erlangen) then at the APC (Paris) [7,8]. For this purpose, in a black box, a motorized wellknown light source moves around the tested OM, with its collimated beam oriented on a quasi-normal angle to the OM surface. This method allows us to measure the effective relative efficiency of the full OM. Three different OMs were tested on 3 different scanning angles. Fig. 4 shows the simulation calibrated on the mean of these 9 measurements, taking in account the standard deviation degree by degree. 4.2. The absolute calibration To measure the absolute efficiency, one can use the well-known K natural decay in the sea water. The coincidences between two close OMs were used to exclude the background noise. Both the configurations, ANTARES and KM3NeT-it, allow us to do a cross check on the total activity. The best fit on both detectors gives the results of Table 1. It is important to note that those results are compatible with the laboratory measurements given in [8].
40
4.3. The angular acceptance The angular acceptance of the OMs is one of the main purpose of this work. In order to get a consensus between the simulation accuracy and the calculation time, the step by step simulation provides a tabulated efficiency of the OMs for the global simulation km3net. This table contains the efficiency for a beam of
Fig. 4. Relative results of the calibration based on the laboratory scan results. The blue points are the experimental means of all the measurements, their errors correspond to the standard deviation, degree by degree, of the corresponding mean points. The black line represents the mean given by the simulation, the green and the red lines represent the predicted standard deviation by the simulation. The efficiency depression at 01 correspond to the central node of the μ-metal grid and the OM glass and photocathode flaws (thickness). The same effect, at lower scale, can be observed at 201. The bump at 551 corresponds to the reflection on the gel/air interface. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)
Table 1 Mean of the 40K coincidence rate between each couple of OM of ANTARES and KM3NeT-it from the data analysis (experimental) and the step by step simulation (simulation). Experiment
ANTARES
KM3NeT-it
Experimental (Hz) Simulated (Hz)
16 15.3
21 21.6
parallel photons hitting the OM at a specific angle (with a beam radius equal to the OM radius).
5. Conclusion and perspectives Thanks to the last improvements of the simulation, such as the wavelength dependency, the geometry refinement and the relative and absolute calibration, the angular acceptance is more accurate, therefore the general simulation km3net is more precise and the efficiency better understood. After the calibrations, the maximal angular acceptance (at 01) correspond to the one measured in laboratory, and the predicted 40K decay rates correspond to the measured ones in the both configurations, which validate the simulation. One of the main perspectives for this step by step simulation is to measure the water properties of the KM3NeT-it site thanks to the LED calibration system. As a function of the different wavelengths and the different distances (from the 4 LED, each one at a different floor) the total absorption and the arrival time due to the scattering of the light in the water. References
Fig. 3. Illustration of the step by step simulation for the ANTARES and KM3NeT-it configurations. Both detectors are simulated in the same water volume, back to back, for the 40K decays (top, Section 4.2). The KM3NeT-it detector prototype is simulated with the bar structures for the angular acceptance (bottom, Section 4.3).
[1] V.V. Elewyck, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 742 (0) (2014) 63. [2] C.A. Nicolau, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 742 (0) (2014) 203. [3] A. Coll, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 484 (13) (2002) 369. [4] C. James, Internal Note: km3net Release.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i
4
C.M.F. Hugon / Nuclear Instruments and Methods in Physics Research A ∎ (∎∎∎∎) ∎∎∎–∎∎∎
[5] D. Motta, S. Schnert, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 539 (12) (2005) 217. [6] D. Motta, Glg4 Simulation. URL 〈http://neutrino.phys.ksu.edu/MAND-sim/MAN D-sim%20talks/DoubleChooz_motta.pdf 〉.
[7] C. Alexandre, Internal Note: Black Box Set-Up on the ANTARES OM. [8] A. Creusot, et al., Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 725 (0) (2013) 144.
Please cite this article as: C.M.F. Hugon, Nuclear Instruments & Methods in Physics Research A (2014), http://dx.doi.org/10.1016/j. nima.2014.11.098i