For separating isotopes (extremely small mass differences), which centrifuge design is generally employed in practice?

Introduction / Context:
Isotope separation requires distinguishing species with minute density differences. Very high centrifugal fields and precise rotors are essential to achieve measurable fractionation.

Given Data / Assumptions:

• Mass differences are tiny; separation factors per stage are small.
• High g-levels and small diffusion paths are required.

Concept / Approach:
Ultracentrifuges operate at extremely high rotational speeds, generating very large centrifugal accelerations. This enhances separation of isotopic species compared to disc-bowl machines, which are intended mainly for liquid–solid or liquid–liquid separations with larger density contrasts.

Step-by-Step Solution:
Identify required g-force for isotope fractionation.Match to ultracentrifuge capabilities.Select ultracentrifuge as the correct design.

Verification / Alternative check:
Isotope enrichment technologies historically leverage ultra-high-speed centrifugation and specialized rotor designs, consistent with this choice.

Why Other Options Are Wrong:
Disc-bowl: inadequate g-levels for isotope work.Batch basket: solid–liquid duty.

Common Pitfalls:
Assuming any centrifuge suits isotope separation; only ultra-high-g devices are effective.

Final Answer:
Ultracentrifuge