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 degrees 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 x 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.

Abbaneo, D., Ahmad, S., Albanese, R., Alexandrov, A., Alicante, F., Aloschi, F., et al. (2025). The SND@LHC neutron shielding. JOURNAL OF INSTRUMENTATION, 20(12), 1-17 [10.1088/1748-0221/20/12/t12002].