The SND@LHC neutron shielding

Abbaneo, D.; Ahmad, S.; Albanese, R.; Alexandrov, A.; Alicante, F.; Aloschi, F.; Androsov, K.; Asawatangtrakuldee, C.; Ayala Torres, M. A.; Bangaru, N.; Bastías Görlich, M.; Battilana, C.; Bay, A.; Bertocco, A.; Betancourt, C.; Bick, D.; Biswas, R.; Blanco Castro, A.; Boccia, V.; Bogomilov, M.; Bonacorsi, D.; Bonivento, W. M.; Bordalo, P.; Boyarsky, A.; Breglio, G.; Buontempo, S.; Cafaro, V.; Campanelli, M.; Camporesi, T.; Canale, V.; Centanni, D.; Cepeda, S.; Cerutti, F.; Chariton, V.; Choi, K. -Y.; Cindolo, F.; Climescu, M.; Crupano, A.; Dallavalle, G. M.; D'Ambrosio, N.; Davino, D.; De Bryas, P. T.; De Asmundis, R.; De Lellis, G.; Del Giudice, G.; De Magistris, M.; De Roeck, A.; De Pasquale, S.; De Rújula, A.; De Simone, D.; De Souza Santos, H.; Diaz Gutierrez, M. A.; Di Crescenzo, A.; Di Cristo, C.; Di Ferdinando, D.; Dinc, C.; Donà, R.; Durhan, O.; Fasanella, D.; Fecarotta, O.; Fedotovs, F.; Ferrillo, M.; Fienga, F.; Fiorillo, A.; Fresa, R.; Funk, W.; Giordano, V.; Golutvin, A.; Graverini, E.; Guiducci, L.; Guler, A. M.; Guliaeva, V.; Haefeli, G. J.; Hagner, C.; Helo Herrera, J. C.; Van Herwijnen, E.; Iaiunese, A.; Ilieva, S.; Infante Cabanas, S. A.; Infantino, A.; Irace, A.; Iuliano, A.; Jacobsson, R.; Kamiscioglu, C.; Kauniskangas, A. M.; Kim, S. H.; Kim, Y. G.; Klioutchnikov, G.; Komatsu, M.; Kuleshov, S.; Lacker, H. M.; Lantwin, O.; Lasagni Manghi, F.; Lauria, A.; Lee, K. Y.; Lee, K. S.; Lee, W. -C.; Liz-Vargas, M.; Loschiavo, V. P.; Mascellani, A.; Majstorovic, M.; Marrazzo, V.; Mei, F.; Miano, A.; Mikulenko, A.; Montesi, M. C.; Morozova, D.; Navarria, F. L.; Nuntiyakul, W.; Ogawa, S.; Ovchynnikov, M.; Paggi, G.; Perrotta, A.; Pinto, R.; Polukhina, N.; Primavera, F.; Prota, A.; Quercia, A.; Ramos, S.; Reghunath, A.; Ronchetti, F.; Rovelli, T.; Ruchayskiy, O.; Ruf, T.; Sadykov, Z.; Scalera, V.; Schmidt-Parzefall, W.; Schneider, O.; Sekhniaidze, G.; Serra, N.; Shaposhnikov, M.; Shchedrina, T.; Shchutska, L.; Shibuya, H.; Sirri, G.; Soares, G.; Sohn, J. Y.; Soto Sandoval, O. J.; Spurio, M.; Steggemann, J.; Strekalina, D.; Timiryasov, I.; Tioukov, V.; Trippl, C.; Ursov, E.; Ustyuzhanin, A.; Vankova-Kirilova, G.; Vasquez, G.; Verguilov, V.; Viegas Guerreiro Leonardo, N.; Vilela, C.; Visone, C.; Wanke, R.; Yamamoto, S.; Yaman, E.; Yang, Z.; Yazici, C.; Yoo, S.; Yoon, C. S.; Zaffaroni, E.; Zamora-Saá, J. A.; Null, Null

doi:10.1088/1748-0221/20/12/t12002

This paper presents the design, construction, and simulation-based validation of the ColdBox, a combined neutron shielding and insulating enclosure for the Scattering and Neutrino Detector at the LHC (SND@LHC). The emulsion films in the detector’s target region require protection from the intense neutron radiation background and a stable environment of 15 ± 1 ◦C and 50–55 % relative humidity for long-term stability. The ColdBox meets these requirements through a dual-layer structure: an external 5 cm plexiglass wall to moderate fast neutrons, and an internal 4 cm layer of borated polyethylene (with 35 % boron content) to capture thermal neutrons. The mechanical design, based on a robust aluminum frame, accommodates the constraints of the TI18 tunnel. FLUKA simulations were used to optimize the shielding configuration, showing a significant reduction in the neutron flux, with a simulated ratio of shielded to unshielded thermal neutron fluence of 2.3 × 10−3. This result is consistent with initial measurements from BatMon detectors. The design also provides a sealed volume for a cooling system to maintain the required temperature and humidity, ensuring the necessary conditions for the emulsion films’ integrity.