An injector for injecting a gas in a material deposition system, the injector comprising: a gas inlet port for coupling the injector to a gas source; a distribution chamber, an intermediate chamber and a delivery manifold arranged in series to provide a flowpath for the gas between the inlet port and at least one delivery aperture through which the gas is injectable in the deposition system, the injector having at least a first distribution chamber outlet aperture (112AS1, 112AS2) through which gas may flow from the distribution chamber to the intermediate chamber and at least first and second intermediate chamber outlet apertures (122AS1, 122AS2) through which gas may flow from the intermediate chamber to the delivery manifold, the intermediate chamber being arranged to divide a flow of gas therethrough between first and second flowpaths (F1, F2), the first and second intermediate chamber outlet apertures (122AS1, 122AS2) being provided in the respective first and second flowpaths (F1, F2), the injector being arranged to allow the first and second flowpaths (F1, F2) to converge within the delivery manifold, wherein each one of the distribution chamber aperture (112AS1, 112AS2), intermediate chamber aperture (122AS1, 122AS2) and delivery manifold aperture is elongate in shape, wherein the first distribution chamber outlet aperture (112AS1, 112AS2) has a longitudinal axis disposed substantially parallel to an x-axis of the injector, wherein the first and second intermediate chamber outlet apertures (122AS1, 122AS2) each have a longitudinal axis disposed substantially parallel to the x-axis of the injector, and wherein longitudinal axes of the first substantially elongate distribution chamber outlet aperture (112AS1, 112AS2) and the first and second elongate intermediate chamber outlet apertures (122AS1, 122AS2) define the apices of an equilateral triangle as viewed along a direction parallel to the x-axis. a gas inlet port for coupling the injector to a gas source; a distribution chamber, an intermediate chamber and a delivery manifold arranged in series to provide a flowpath for the gas between the inlet port and at least one delivery aperture through which the gas is injectable in the deposition system, the injector having at least a first distribution chamber outlet aperture (112AS1, 112AS2) through which gas may flow from the distribution chamber to the intermediate chamber and at least first and second intermediate chamber outlet apertures (122AS1, 122AS2) through which gas may flow from the intermediate chamber to the delivery manifold, the intermediate chamber being arranged to divide a flow of gas therethrough between first and second flowpaths (F1, F2), the first and second intermediate chamber outlet apertures (122AS1, 122AS2) being provided in the respective first and second flowpaths (F1, F2), the injector being arranged to allow the first and second flowpaths (F1, F2) to converge within the delivery manifold, wherein each one of the distribution chamber aperture (112AS1, 112AS2), intermediate chamber aperture (122AS1, 122AS2) and delivery manifold aperture is elongate in shape, wherein the first distribution chamber outlet aperture (112AS1, 112AS2) has a longitudinal axis disposed substantially parallel to an x-axis of the injector, wherein the first and second intermediate chamber outlet apertures (122AS1, 122AS2) each have a longitudinal axis disposed substantially parallel to the x-axis of the injector, and wherein longitudinal axes of the first substantially elongate distribution chamber outlet aperture (112AS1, 112AS2) and the first and second elongate intermediate chamber outlet apertures (122AS1, 122AS2) define the apices of an equilateral triangle as viewed along a direction parallel to the x-axis.