Project 8.1 = Basic Thermal Radiation Measurements - W. B. Plum - NRDL 8.2 = Material Exposed to Thermal Radiation Project 8.1 is "Basic Thermal Radiation Measurements", on the air drop ~ Cherokees; Our pricrity here is we plan to man stations at Dog, George and How. Our second priority is Zuni; stations on William or Victor and on Nan, Oboe and How, Next priority is a surface shot on Eniwetok Atolls the only one we are able to cover at the present time is the one on Runit, Lacrosse I, We did want to cover Pueblo, but it looks like it will be fired before we are able to. move our equip- ment from Bikini Atoll. The data that we are taking will be to measure the thermal radiant power as a function of time by means of two instruments, a bolometer which has a time resolution of 50 microseconds, then the radiometer which has a time resolution of 20 milliseconds. By our calorimeter we measure the total energy per unit area. We will also have broad band filters to measure the broad band distribution of energy per unit area, and correlate these data with all the data from operations beginning with GREENHOUSE. We are also making some field of view measurements where we will have our thermal instruments to measure field of view 11, 22, 45, 90 and 180 degrees. The byproduct of our field of view measurements and our three stations will be such that we will be able to get the total atmospheric transmission. Here we have the ideal case of a four pi source, and various fields of view from 11° up to 180°, to give us information to correct for field of view and also information as to the transmissivity per mile or per unit of the atmosphere. With the spectrometer, one on George and one on How, in the planning stages. For the project not approved we are getting 66 2/3% of we get the spectral distribution, from which we can draw to compute the effect of color temperatures. We can also get the transmission coefficient for the various wave length bands since the two spectrometers will be identical. Together with another spectrometer, mentioned later by Dr. Zirkind, this will give . us a correlation of data along a ground path and along an air path. The spectro-. meter and bolometer will give us time to minimum and the time to second maximun, and from the spectrometer and bolometer we can get the time to first maximm. I mention at this time we are giving technical support to 14 projects which have been approved, another project which has not been approved and another which is the information which they want. On this operation we are expecting to get some points on our curves for the larger yield Mt weapms. We got quite a few points from 10 to 50 kt and quite a few below 10 on TEAPOT, and we find, as they develop their weapons and reduce the mass, they begin to fall in with the forma W to 1/2 power. One thing worries us a little and that is the relation between the thermal and the chemical yield. The equation for that is the thermal yield is proportional to the chemical but you have Wto the .94 power. We want to know what happens to that Wto the .06 power mergy. It doesn't seem the equation is reasonable. should be W to the one power. During this operation we will get a point far out on the graph so we can draw the straight line and get the answer, There other unsolved questions which make Cherokee and Zuni priority shots. There some question as to the color temperature of these larger weapons. There is tl SE ae It enough are is also