Abstract: A projection optical system comprising a first lens having a positive refractive power, a second lens having a negative refractive power and a third lens having a positive refractive power, the lenses being arranged in ascending order in number from the side of an illuminated object, wherein when the optical system is regarded as an imaging optical system receiving a light beam from the side of the illuminated object, the effective focal length is represented by f, the total refractive power is represented by Pt=1/f, each lens surface of the three lenses are referred to as a first lens surface to a sixth lens surface from the side of the illuminated object, the refractive power is represented by Pt, the center thickness of the second lens is represented by L2 and f number is represented by F, the expressions 1.3 < P ? 5 / Pt 0.1 < L ? 2 / f < 0.25 F < 0.

Abstract: A diffuser provided with plural shapes obtained by translation on an xy plane of at least one of z=g(x, y) and z=?g(x, y), z=g(x, y) being a smooth function within a rectangle having sides of length of s in x direction and sides of length of t in y direction, the origin being the center of the rectangle, wherein on the sides of the rectangle, g ? ( x , y ) = 0 , ? ? g ? ( x , y ) ? x = 0 , ? ? g ? ( x , y ) ? y = 0 , ? ? 2 ? g ? ( x , y ) ? x 2 = 0 , and ? 2 ? g ? ( x , y ) ? y 2 = 0 , and wherein z=g(x, y) has a single vertex at (xv,yv) g(x,y)=h1(x)·h2(y), first derivative of z=h1(x) is continuous in ( - s 2 , s 2 ) , second derivative of z=h1(x) has a single point of discontinuity in ( - s 2 , x v ) and ? ( x v , s 2 ) , first derivative of z=h2(y) is continuous in ( - t 2 , t 2 ) , and second derivative of z=h2(y) has a single

Abstract: A diffuser provided with plural shapes obtained by translation on an xy plane of at least one of z=g(x, y) and z=?g(x, y), z=g(x, y) being a smooth function within a rectangle having sides of length of s in x direction and sides of length of t in y direction, the origin being the center of the rectangle, wherein on the sides of the rectangle, g ? ( x , y ) = 0 , ? ? g ? ( x , y ) ? x = 0 , ? ? g ? ( x , y ) ? y = 0 , ? ? 2 ? g ? ( x , y ) ? x 2 = 0 , and ? 2 ? g ? ( x , y ) ? y 2 = 0 , and wherein z=g(x, y) has a single vertex at (xv,yv) g(x,y)=h1(x)·h2(y), first derivative of z=h1(x) is continuous in ( - s 2 , s 2 ) , second derivative of z=h1(x) has a single point of discontinuity in ( - s 2 , x v ) and ? ( x v , s 2 ) , first derivative of z=h2(y) is continuous in ( - t 2 , t 2 ) , and second derivative of z=h2(y) has a sin

Abstract: A particle beam generator has a vacuum chamber, a magnet which generates a constant magnetic field in the vacuum chamber, acceleration electrodes which generates a magnetic field in a direction perpendicular to the direction of the magnetic field generated by the magnet in the vacuum chamber, a take-out electrode which takes out charged particles accelerated in the vacuum chamber; and a target cell provided at a position at which the charged particles taken out by the taken-out electrode strikes. At least a part of surfaces exposed to the charged particles of the vacuum chamber, the acceleration electrodes, the take-out electrode and/or the target cell is made of a material including an element having atomic number larger than copper.

Abstract: A particle beam generator has a vacuum chamber, a magnet which generates a constant magnetic field in the vacuum chamber, acceleration electrodes which generates a magnetic field in a direction perpendicular to the direction of the magnetic field generated by the magnet in the vacuum chamber, a take-out electrode which takes out charged particles accelerated in the vacuum chamber; and a target cell provided at a position at which the charged particles taken out by the taken-out electrode strikes. At least a part of surfaces exposed to the charged particles of the vacuum chamber, the acceleration electrodes, the take-out electrode and/or the target cell is made of a material including an element having atomic number larger than copper.