2.2.2 Instrument Description, Calibration, and Respoose
Both X-ray and total thermal instruments vere designed to operate as
ballistic calorimeters; upon absorbing a large pulse of radiant energy in a
short time interval, the instruments reach thermal equilibrius some tise later.
The anount of energy absorbed by such a calorineter is directly proportional
to the product of the resulting tesperature rise tises its therasl onss.
Each X-ray transducer consisted of a pair of these caloriseters aounted
behind appropriate filter windows as shown in Fig. 2.16.
These filters served
three equally iaportant purpeses:
(1) They cejected radiation of longer wavelength than desired;
(2) They attenuated incident X-ray enerzy in such a manner as to preveot
waporization of the calorimeter surface and a consequent loss of energy;
(3) They yielded inforzation on rhe spectral distribution of X-ray enerzy
from which the effeccive radiating teaperature could be obcairced.
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