First results from the DEAP-3600 dark matter search with argon at SNOLAB by Amaudruz, P-A, Baldwin, M, Batygov, M, Beltran, B, Bina, CE, Bishop, D, Bonatt, J, Boorman, G, Boulay, MG, Broerman, B, Bromwich, T, Bueno, JF, Butcher, A, Cai, B, Chan, S, Chen, M, Chouinard, R, Cleveland, BT, Cranshaw, D, Dering, K, DiGioseffo, J, Dittmeier, S, Duncan, FA, Dunford, M, Erlandson, A, Fatemighomi, N, Florian, S, Flower, A, Ford, RJ, Gagnon, R, Giampa, P, Golovko, VV, Gorel, P, Gornea, R, Grace, E, Graham, K, Grant, DR, Gulyev, E, Hakobyan, R, Hall, A, Hallin, AL, Hamstra, M, Harvey, PJ, Hearns, C, Jillings, CJ, Kamaev, O, Kemp, A, Kuźniak, M, Langrock, S, Zia, FL, Lehnert, B, Lidgard, JJ, Lim, C, Lindner, T, Linn, Y, Liu, S, Majewski, P, Mathew, R, McDonald, AB, McElroy, T, McGinn, T, McLaughlin, JB, Mead, S, Mehdiyev, R, Mielnichuk, C, Monroe, J, Muir, A, Nadeau, P, Nantais, C, Ng, C, Noble, AJ, O'Dwyer, E, Ohlmann, C, Olchanski, K, Olsen, KS, Ouellet, C, Pasuthip, P, Peeters, SJM, Rand, ET, Rau, W, Rethmeier, C, Retière, F, Seeburn, N, Shaw, B, Singhrao, K, Skensved, P, Smith, B, Smith, NJT, Sonley, T, Soukup, J, Stainforth, R, Stone, C, Strickland, V, Sur, B, Tang, J, Taylor, J, Veloce, L, Vázquez-Jáuregui, E, Walding, J, Ward, M, Westerdale, S, Woolsey, E, Zielinski, J