Abstract: A reflective mask blank includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and a phase shift film that shifts a phase of the EUV light, the substrate, the multilayer reflective film, the protection film, and the phase shift film being arranged in this order. The phase shift film contains at least one first element X1 selected from the first group consisting of ruthenium (Ru), iridium (Ir), platinum (Pt), palladium (Pd), and gold (Au), and at least one second element X2 selected from the second group consisting of oxygen (O), boron (B), carbon (C), and nitrogen (N). In the phase shift film, a chemical shift of a peak of 3d5/2 or a peak of 4f7/2 of the first element X1 observed by X-ray electron spectroscopy is less than 0.3 eV.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from the main chamber central axis at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through the precombustion chamber central axis and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion. The cross-sectional area of a specific near nozzle hole which is at least one nozzle hole in the near-ignition region is smaller than the cross-sectional area of a specific far nozzle hole which is at least one nozzle hole in the far-ignition region.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber including a small-diameter cylinder chamber communicating with the main combustion chamber via a plurality of nozzle holes and a large-diameter cylinder chamber, an ignition device disposed in the large-diameter cylinder chamber of the precombustion chamber, and a precombustion-chamber-gas supply device for supplying a precombustion-chamber fuel gas to the precombustion chamber not via the main combustion chamber.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber including a small-diameter cylinder chamber communicating with the main combustion chamber via a plurality of nozzle holes and a large-diameter cylinder chamber, an ignition device disposed in the large-diameter cylinder chamber of the precombustion chamber, and a precombustion-chamber-gas supply device for supplying a precombustion-chamber fuel gas to the precombustion chamber not via the main combustion chamber.

Abstract: A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from the main chamber central axis at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through the precombustion chamber central axis and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion. The cross-sectional area of a specific near nozzle hole which is at least one nozzle hole in the near-ignition region is smaller than the cross-sectional area of a specific far nozzle hole which is at least one nozzle hole in the far-ignition region.

Abstract: A precombustion-chamber engine includes a cylinder, a cylinder head disposed on a top of the cylinder, and a piston reciprocably disposed within the cylinder. A main combustion chamber is defined between the piston and the cylinder head. The cylinder head includes a precombustion-chamber forming part which defines a precombustion chamber communicating with the main combustion chamber through a nozzle. The precombustion chamber includes a cylindrical first passage part extending upwardly from the nozzle, a second passage part extending upwardly from the first passage part and having an upwardly-increasing cross-sectional area, and a cylindrical space part which extends upwardly from the second passage part and in which a spark plug is disposed. Center O of a cross-section, orthogonal to straight line L, of the second passage part is eccentric with respect to straight line L composed of an axis of the first passage part and an extended line of the axis.

Abstract: A precombustion-chamber engine includes a cylinder, a cylinder head disposed on a top of the cylinder, and a piston reciprocably disposed within the cylinder. A main combustion chamber is defined between the piston and the cylinder head. The cylinder head includes a precombustion-chamber forming part which defines a precombustion chamber communicating with the main combustion chamber through a nozzle. The precombustion chamber includes a cylindrical first passage part extending upwardly from the nozzle, a second passage part extending upwardly from the first passage part and having an upwardly-increasing cross-sectional area, and a cylindrical space part which extends upwardly from the second passage part and in which a spark plug is disposed. Center O of a cross-section, orthogonal to straight line L, of the second passage part is eccentric with respect to straight line L composed of an axis of the first passage part and an extended line of the axis.