  The MANTA (Modular Adjustable Negative Triangularity ARC-class) design study
investigated how negative-triangularity (NT) may be leveraged in a compact,
fusion pilot plant (FPP) to take a ``power-handling first" approach. The result
is a pulsed, radiative, ELM-free tokamak that satisfies and exceeds the FPP
requirements described in the 2021 National Academies of Sciences, Engineering,
and Medicine report ``Bringing Fusion to the U.S. Grid". A self-consistent
integrated modeling workflow predicts a fusion power of 450 MW and a plasma
gain of 11.5 with only 23.5 MW of power to the scrape-off layer (SOL). This low
$P_\text{SOL}$ together with impurity seeding and high density at the
separatrix results in a peak heat flux of just 2.8 MW/m$^{2}$. MANTA's high
aspect ratio provides space for a large central solenoid (CS), resulting in
${\sim}$15 minute inductive pulses. In spite of the high B fields on the CS and
the other REBCO-based magnets, the electromagnetic stresses remain below
structural and critical current density limits. Iterative optimization of
neutron shielding and tritium breeding blanket yield tritium self-sufficiency
with a breeding ratio of 1.15, a blanket power multiplication factor of 1.11,
toroidal field coil lifetimes of $3100 \pm 400$ MW-yr, and poloidal field coil
lifetimes of at least $890 \pm 40$ MW-yr. Following balance of plant modeling,
MANTA is projected to generate 90 MW of net electricity at an electricity gain
factor of ${\sim}2.4$. Systems-level economic analysis estimates an overnight
cost of US\$3.4 billion, meeting the NASEM FPP requirement that this
first-of-a-kind be less than US\$5 billion. The toroidal field coil cost and
replacement time are the most critical upfront and lifetime cost drivers,
respectively.
