Abstract: A turbine blade includes an airfoil portion having a pressure surface and a suction surface each of which extends between a leading edge and a trailing edge, and a platform including an end wall to which a base-end portion of the airfoil portion is connected. The end wall includes a concave portion on suction surface disposed at least in a region of suction surface of the end wall, and a convex portion on pressure surface disposed at least in a region of pressure surface of the end wall. The concave portion on suction surface has a bottom point located on an axially upstream side of a tangent point on the suction surface, the suction surface having a tangential line extending in an axial direction through the tangent point.

Abstract: A turbine blade includes an airfoil portion having a pressure surface and a suction surface each of which extends between a leading edge and a trailing edge, and a platform including an end wall to which a base-end portion of the airfoil portion is connected. The end wall includes a concave portion on suction surface disposed at least in a region of suction surface of the end wall, and a convex portion on pressure surface disposed at least in a region of pressure surface of the end wall. The concave portion on suction surface has a bottom point located on an axially upstream side of a tangent point on the suction surface, the suction surface having a tangential line extending in an axial direction through the tangent point.

Abstract: The invention relates to a droplet dispensing device (4) comprising a reservoir (9) for containing a liquid medium (10), an outlet (11) for dispensing droplets of said liquid medium (10) from said reservoir (9), an actuation means (12) for generating and transmitting a mechanical oscillation at an excitation frequency, and a resonant structure comprising a piston (15) coupled to said actuation means (12) for transmitting said mechanical oscillation to the liquid medium (10) contained in said reservoir (9) such that droplets are formed from said liquid medium (10), wherein a resonance frequency of said resonant structure is sufficiently close to said excitation frequency, such that resonance occurs. The invention further relates to a UV or X-ray light source, comprising a droplet dispensing device (4) according to the invention, and a method for providing a stream, in particular a monodisperse stream, of droplets by means of the droplet dispensing device (4).

Abstract: The invention relates to a device (100) for generating UV or X-ray radiation (R) by means of a plasma (10), comprising a first compartment (110), a dispensing device (5), which is adapted to provide a target material (80) in the first compartment (10), an excitation light source (13) for providing an excitation light beam (90), and a buffer gas inlet (130) and/or a buffer gas outlet (140) for providing a buffer gas flow (B) along the direction (D) of the excitation light beam (90) in the first compartment (110), wherein the first compartment (110) is adapted to be at least partially heated by a heating device (150). The invention further relates to a method for generating UV or X-ray radiation (R) by means of the device (100).

Abstract: The invention relates to a device (100) for generating UV or X-ray radiation (R) by means of a plasma (10), comprising a first compartment (110), a dispensing device (5), which is adapted to provide a target material (80) in the first compartment (10), an excitation light source (13) for providing an excitation light beam (90), and a buffer gas inlet (130) and/or a buffer gas outlet (140) for providing a buffer gas flow (B) along the direction (D) of the excitation light beam (90) in the first compartment (110), wherein the first compartment (110) is adapted to be at least partially heated by a heating device (150).

Abstract: A method for controlling an interaction between droplet targets and a high power and high-repetition-rate laser beam at a laser focus position of the laser beam including providing a droplet generator for generating a train of droplets as a droplet target with a predetermined droplet frequency and velocity in a predetermined direction; providing a high power, high-repetition-rate laser for emitting a pulsed laser beam, which is focused in the laser focus position; aligning the droplet generator such that the train of droplets runs through the laser focus position; generating a train of droplets as a droplet target; and emitting a pulsed laser beam in synchronization with the train of droplets, such that the droplet target interacts with the pulsed laser beam at the laser focus position.

Abstract: The invention relates to a droplet dispensing device (4) comprising a reservoir (9) for containing a liquid medium (10), an outlet (11) for dispensing droplets of said liquid medium (10) from said reservoir (9), an actuation means (12) for generating and transmitting a mechanical oscillation at an excitation frequency, and a resonant structure comprising a piston (15) coupled to said actuation means (12) for transmitting said mechanical oscillation to the liquid medium (10) contained in said reservoir (9) such that droplets are formed from said liquid medium (10), wherein a resonance frequency of said resonant structure is sufficiently close to said excitation frequency, such that resonance occurs. The invention further relates to a UV or X-ray light source, comprising a droplet dispensing device (4) according to the invention, and a method for providing a stream, in particular a monodisperse stream, of droplets by means of the droplet dispensing device (4).

Abstract: An optical collector (15) for collecting extreme ultraviolet radiation or EUV light generated at a central EUV production site comprises a reflective shell (25). To cope with thermal loading of the collector and avoid deformations, the reflective shell (25) is mounted on a support structure (24), such that a cooling channel (29) is established between the back side of the reflective shell (25) and the support structure (24), the thickness of the reflective shell (25) is substantially reduced, such that the convective heat transfer between the back side of the reflective shell (25) and a cooling medium (26) flowing through the cooling channel (29) dominates the process of removing heat from the reflective shell (25) with respect to heat conduction, and a cooling circuit (33) is connected to the cooling channel (29); to supply a cooling medium (26) to the cooling channel (29) with a controlled coolant pressure and/or mass flow.

Abstract: A droplet dispensing device includes a reservoir for receiving a liquid material, an outlet nozzle in fluid communication with the reservoir and a piezoelectric actuating means acting on the liquid material at the outlet nozzle to exit the outlet nozzle in a sequence of droplets. A piezoelectric actuating means that includes a piston, which is actuated by a piezoelectric actuator at one end and dips the other, free end into the liquid material is provided just upstream of the outlet nozzle.

Abstract: A method for controlling an interaction between droplet targets and a high power and high-repetition-rate laser beam at a laser focus position of the laser beam including providing a droplet generator for generating a train of droplets as a droplet target with a predetermined droplet frequency and velocity in a predetermined direction; providing a high power, high-repetition-rate laser for emitting a pulsed laser beam, which is focused in the laser focus position; aligning the droplet generator such that the train of droplets runs through the laser focus position; generating a train of droplets as a droplet target; and emitting a pulsed laser beam in synchronization with the train of droplets, such that the droplet target interacts with the pulsed laser beam at the laser focus position

Abstract: A droplet dispensing device includes a reservoir for receiving a liquid material, an outlet nozzle in fluid communication with the reservoir and a piezoelectric actuating means acting on the liquid material at the outlet nozzle to exit the outlet nozzle in a sequence of droplets. A piezoelectric actuating means that includes a piston, which is actuated by a piezoelectric actuator at one end and dips the other, free end into the liquid material is provided just upstream of the outlet nozzle.

Abstract: The extreme ultraviolet light source comprises a production site capable of producing extreme ultraviolet radiation in a laser-produced plasma (3), and a collector optics (6) for collimating the extreme ultraviolet radiation. A pressurized influx of gas forms a gas curtain between the production site and the collector optics (6) in order to protect the collector optics (6) from debris (4) generated at the production site. The gas influx is directed in a way that it follows the surface of the collector optics (6). By thus shielding the collector optics (6) from the debris (4) its lifetime is enhanced. The shielding gas can further be used for cooling the collector optics (6).

Abstract: The invention relates to a beam line (30) for a source of extreme ultraviolet (EUV) radiation, wherein a EUV-radiating plasma is generated by irradiating droplets of a suitable target material with a focused laser beam (5) at a plasma generation point, said beam line (30) comprising within a vacuum chamber (7): a beam delivery system (2) comprising a focusing lens and means for cooling and shielding said focusing lens; a EUV mirror collector (1), which collects and focuses the radiated EUV in a EUV beam (6) at an intermediate focus (IF); a beam dump (3) capable of damping at least a portion of the laser beam (5) without imposing a shadow on the collected and focused EUV beam (6); and an intermediate focus module (4) for blocking particles from leaving the vacuum chamber (7) with the EUV beam (6).

Abstract: An optical collector (15) for collecting extreme ultraviolet radiation or EUV light generated at a central EUV production site comprises a reflective shell (25). To cope with thermal loading of the collector and avoid deformations, the reflective shell (25) is mounted on a support structure (24), such that a cooling channel (29) is established between the back side of the reflective shell (25) and the support structure (24), the thickness of the reflective shell (25) is substantially reduced, such that the convective heat transfer between the back side of the reflective shell (25) and a cooling medium (26) flowing through the cooling channel (29) dominates the process of removing heat from the reflective shell (25) with respect to heat conduction, and a cooling circuit (33) is connected to the cooling channel (29); to supply a cooling medium (26) to the cooling channel (29) with a controlled coolant pressure and/or mass flow.

Abstract: The extreme ultraviolet light source comprises a production site capable of producing extreme ultraviolet radiation in a laser-produced plasma (3), and a collector optics (6) for collimating the extreme ultraviolet radiation. A pressurized influx of gas forms a gas curtain between the production site and the collector optics (6) in order to protect the collector optics (6) from debris (4) generated at the production site. The gas influx is directed in a way that it follows the surface of the collector optics (6). By thus shielding the collector optics (6) from the debris (4) its lifetime is enhanced. The shielding gas can further be used for cooling the collector optics (6).

Abstract: A turbine blade (1) with a side surface (7) having an aerodynamic profile. The turbine blade (1) further comprises an end surface (6) and is mounted in a turbine, whereby the end surface (6) is delimited by a gap from a casing (8) of the turbine. The end surface (6) comprises a recess (2) which is shaped such that it acts as an improved aerodynamic seal.