Abstract: A measurement system to determine a deformation of an object having a front surface, a back surface and a pattern. The measurement system includes a processor system and an interferometer system. The interferometer system has a radiation source and a detector system. The source is configured to emit, to each of a plurality of locations on the object, measurement beams in order to generate, at each of the respective plurality of locations, reflected measurement beams off the front and back surfaces of the object respectively. The detector system is configured to receive the respective reflected measurement beams and output signals representative of the received reflected measurement beams to the processor system. The processor system is configured to receive the signals; determine, based on the signals as received, a characteristic of the object; and determine a deformation of the pattern based on the characteristic.

Abstract: An apparatus comprising a heat-sensitive device (F); a radiative element (RE), the radiative element in operation generating first electromagnetic radiation (ER), the first radiation propagating towards the heat-sensitive device; and a radiation-shielding device (20) arranged between the radiative element and the heat-sensitive device such that, in operation, the first radiation impinges on the radiation-shielding device. The radiation-shielding device comprises a first shield element (21) having a first fluid channel (215) arranged therein, the first shield element having a first surface (213) and a second surface (214), the first surface being arranged closer to the radiative element than the second surface; and a second shield element (22) having a second fluid channel (225) arranged therein, the second shield element having a third surface (223) and a fourth surface (224), the third surface being arranged closer to the radiative element than the fourth surface.