In an x-ray tube, which component directs the electron beam toward the focal spot on the anode?

In an x-ray tube, which component directs the electron beam toward the focal spot on the anode?

• A. Focusing Cup
• B. Anode Target
• C. Filament
• D. Collimator

Answer: (A)

Directing the electron beam to the focal spot is accomplished by the focusing cup. The filament emits electrons, but without steering they would spread out. The focusing cup is a negatively charged, concave metal piece surrounding the filament. Its shape and electrostatic field push and guide the electrons toward the axis so they converge onto a small focal spot on the anode, making X-ray production efficient and producing a sharp image. The anode target is where the electrons actually strike to generate X-rays, the filament is the electron source, and the collimator only shapes the X-ray beam after it’s produced.

Directing the electron beam to the focal spot is accomplished by the focusing cup. The filament emits electrons, but without steering they would spread out. The focusing cup is a negatively charged, concave metal piece surrounding the filament. Its shape and electrostatic field push and guide the electrons toward the axis so they converge onto a small focal spot on the anode, making X-ray production efficient and producing a sharp image. The anode target is where the electrons actually strike to generate X-rays, the filament is the electron source, and the collimator only shapes the X-ray beam after it’s produced.