blackbody energy detector, from Liboff's QM

[cstalg]

1. The problem statement, all variables and given/known data

Problem 2.11 of Liboff's Introductory Quantum Mechanics, 1st edition

Suppose that you are inside a blackbody radiation cavity which is at temperature T. Your job is to measure the energy in the radiation field in the frequency interval 10^{14} to 89 \times 10^{14} Hz. You have a detector that will do the job. For best results, should the temperature of the detector T' be T' > T, T' = T, T' < T, or T' = 0; or is the temperature of the detector irrelevant to the measurement?


2. Relevant equations
There seems not lots of calculation.


3. The attempt at a solution
I've no idea how such a detector works. Dose it look like a blackbody itself which absorbs the radiation in the cavity?

[Antiphon]

Your attemp at a solution is halfway to the answer. Keep asking "what if."

The detectors work by absorbing a quantum and converting that event into a signal.

[cstalg]

I think the temperature of the detector should be as low as possible, so that no thermal noise will disturb the observation. So it's T'=0. Is that right?