There are different levels of artificial wormhole construction:
A Type I or higher civilization may build a particle accelerator the size of the asteroid belt. A circular beam of protons would be sent around the belt, guided by gigantic magnets. On Earth, particles are sent inside a large circular tube containing a vacuum. But since the vacuum of outer space is better than any vacuum on the Earth, this accelerator does not need a tube at all. All it needs is a series of gigantic magnetic stations placed strategically around the belt, making a circular path for the proton beam. Each time the protons go past a station, a surge of electrical energy powers the magnets, which kick the proton beam so that it moves to the next station at the correct angle. Each time the proton beam passes by a magnetic station, more energy is pumped into the beam in the form of laser power, until it gradually reaches the Planck energy. Once the accelerator attains this energy, it can focus that energy onto a single point. A wormhole should open up there. It would then be injected with enough negative energy to stabilize it so it doesn’t collapse.
Type II or higher use a forge (sometimes called a weylforge) which consists of an entire array of devices all handling different aspects of wormhole construction. Power needed is about 3% to 10% of the daily power output of the Sun (about 1030 J). This is generated by collector arrays orbiting the nearest star, or conversion reactors operating either beneath a local stellar surface or in close proximity to the forge using material collected from the local Kuiper belt or Oort Cloud. The energy collected is transmitted to the forge in the form of high power laser or maser beams and then stored using magmatter-based capacitor systems built into the wormhole production module. To produce a wormhole, the forge first accumulates energy in its capacitors while carefully aligning a seed and each element in the production module to ensure that all of the particle beams produced by the accelerator arrays will strike at precisely the right time and angle with energies approaching that of the Big Bang itself. This creates rifts in the quantum foam and a wormhole is briefly captured and held stable for many times longer than it would normally persist. The extraction kernel activates and induces a state of extreme vacuum fluctuation in the fabric of spacetime at the center of the forge. These vacuum fluctuations are fed into the temporarily stable wormhole, gradually converting it into a usable gateway and eventually self-maintaining and sufficiently stable to allow transit of interstellar traffic.
Likely only with Type III a hyper-forge uses the energy output of a neutron star rather than a conventional sun for power. Hyper-forges employ a modified Matrioshka multi-shell design to capture as much of the neutron star's output as possible. Neutron stars radiate from 20,000 to 100,000 times the energy of a Sun-type star.