Speaker
Description
The uncertainty in the initial neutrino flux is the main limitation for the measurements of the absolute neutrino cross sections. The ENUBET project (Enhanced NeUtrino BEams from kaon Tagging, Horizon-2020 ERC-CoG grant, 2016-2021) is developing an innovative technique to produce intense sources of electron neutrinos with a ten-fold improvement in accuracy.
A key element of the project is the instrumentation of a decay tunnel with detectors being able to monitor large-angle positrons arising from Ke3 decays and to discriminate them from the background of charged and neutral pions.
An e+/pi separation capability of about 2% as well as a high e+ efficiency is required for a diffuse particle source over a length of several tens of meters. Additional constraints, due to the harsh beam environment, involve radiation hardness and fast response.
For this purpose we have developed a specialized shashlik calorimeter (steel-scintillator) with a compact readout based on small-area Silicon Photo Multipliers coupled to WLS fibers. The Ultra-Compact modules are composed of 1.5 cm thick steel absorbers coupled to 5 mm thick plastic scintillators tiles with TiO reflective painting. A matrix of 3 x 3 fibers run transversely with a density of one fiber/cm2 and an overall surface of about 10cm^2. Fibers are coupled individually to HD SiPM with 20x20 um cells mounted on a custom PCB allowing reduce the dead zones between adjacent modules to an extremely small level compared to "fiber bundling" configurations. This setup allows a very effective longitudinal segmentation or electron/hadron separation.
In this talk we will present the results of the experimental campaign performed in 2016-2017 at the CERN-PS East Area (T9 beam line) and the future tests planned in May and November 2018. The prototype tagger fulfills the project requirements in terms of energy resolution, linearity and electron/pion identification.
We will also discuss the characterization of SiPM of different cell size (12μm and 15 μm) before and after being exposed to neutron fluxes up to 10^{12}/cm^2 at the INFN-LNL CN accelerator facility in June 2017.
Alternative options for the active material have also been investigated. In particular we have successfully characterized with CERN beams a (12 X0) shashlik calorimeter based on polysiloxane scintillators. These are scintillators which come in liquid form, are poured around the fiber arrays and finally made solid with a thermal treatment. This scheme is very appealing for practical reasons related to the construction of such a large calorimeter. Energy resolution, linearity, spacial uniformity and light yields have been assessed and are very promising.
References
- G. Ballerini et al, Testbeam performance of a shashlik calorimeter with fine-grained longitudinal segmentation, arXiv:1801.06167 (pdf), JINST 13 (2018) P01028.
- A. Berra et al., Shashlik Calorimeters With Embedded SiPMs for Longitudinal Segmentation, IEEE Trans. Nucl. Sci. 64 (2017) no.4, 1056-1061
- A. Berra et al., Longitudinally segmented shashlik calorimeters with SiPM readout, Nucl. Instrum. Meth. A845 (2017) 511-514, pdf
- M. Pozzato et al. High precision flux measurements with ENUBET, J. Phys. Conf. Ser. 888 (2017) no.1, 012119
- F. Pupilli et al., The ERC ENUBET Project: high precision neutrino flux measurements in conventional neutrino beams Proceedings of NuPhys 2016, arXiv:1705.00150 (pdf)
- A. Longhin et al., High precision flux measurements in conventional neutrino beams: the ENUBET project, PoS NOW2016 (2017) 035
- F. Terranova et al., The ENUBET project: high precision neutrino flux measurements in conventional neutrino beams, PoS (EPS-HEP2017) 138
- A. Meregaglia et al., ENUBET: Enhanced NeUtrino BEams from kaon Tagging, JINST 11 (2016) no.12, C12040
- A. Berra et al. Enabling precise measurements of flux in accelerator neutrino beams: the ENUBET project CERN-SPSC-2016-036 / SPSC-EOI-014, 05/10/2016
Secondary topics
fast timing, novel materials, simulation
| Applications | Design concepts for future calorimeter at the intensity frontier |
|---|---|
| Primary topic | Scintillators |
