Technical Design Report of the Spin Physics Detector at NICA

The Spin Physics Detector Collaboration proposes to install a universal detector in the second interaction point of the NICA collider under construction (JINR, Dubna) to study the spin structure of the proton and deuteron and other spin-related phenomena using a unique possibility to operate with polarized proton and deuteron beams at a collision energy up to 27 GeV and a luminosity up to 1032 cm−2 s−1. As the main goal, the experiment aims to provide access to the gluon TMD PDFs in the proton and deuteron, as well as the gluon transversity distribution and tensor PDFs in the deuteron, via the measurement of specific single- and double-spin asymmetries using different complementary probes, such as charmonia, open charm, and prompt photon production processes. Other polarized and unpolarized physics is possible, especially at the first stage of NICA operation with reduced luminosity and collision energy of the proton and ion beams. This paper is dedicated exclusively to technical issues of the SPD setup construction.Corrected: 5 February 2025 (the surname of one of the authors was initially misspelled (M. Bolsunovskya), the correct spelling is M. Bolsunovskaya). 23 April 2025 (the surname of one of the authors was initially misspelled (A. Seleznev), the correct spelling is A. Selezenev).