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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Year: 1949
Shielded room measurements, Final report

Shielded room measurements, Final report

Date: February 22, 1949
Creator: Stanton, J.S.
Description: The attenuation of electro-statically and electro-magnetically shielded rooms in the ``E,`` ``R,`` ``I,`` and ``T`` Buildings was measured so that corrective measure could be taken if the attenuation was found to be low. If remedial measures could not be taken, the shortcomings of the rooms would be known. Also, the men making the measurements should oversee construction and correct errors at the time. The work was performed by measuring the attenuation at spot frequencies over the range of from 150 kilocycles to 1280 megacycles with suitable equipment mounted in small rubber-tried trucks. The attenuation was determined by ``before and after`` shielding and/or ``door open and door closed`` measurements after installation of copper shielding. In general, attenuation in the frequency range of approximately 10 to 150 mc. was good and was of the order expected. At frequencies in the range of 150 mc. to 1280 mc., the attenuation curve was more erratic; that is, at certain frequencies a severe loss of attenuation was noted, while at others, the attenuation was very good. This was mainly due to poor or faulty seals around doors and pass windows. These poor seals existed in the ``T,`` ``E,`` and ``I`` Buildings because the doors were ...
Contributing Partner: UNT Libraries Government Documents Department
Electronics progress report, March 1--31, 1949

Electronics progress report, March 1--31, 1949

Date: December 31, 1949
Creator: Heyd, J.W. & Ohmart, P.E.
Description: With the completion of tests of the prototype cathode-follower, it was decided to produce three more models. These have been constructed and pass the same pulse as that of the prototype. Drawings are being made of these units. By the time these units had been completed, the amplifier of the scaler was modified so that its frequency response was essentially flat up to 4.5 megacycles. Using this amplifier and the cathode-follower, a study of the pulse shapes was made and four different pulse shapes were found to be obtainable. A band pass network between the B-wall tube and the input of the cathode-follower provided a very substantial improvement over the shunt peaking network with a band pass of 1.8 to 6.5 megacycles and provided clean, uniform pulses. Plans are being made to experiment with a filter of narrower band pass, which, if satisfactory, will produce greater amplitude. When the final band pass has been determined, a combination of shunt peaking and band pass networks should provide a net gain of 30% in amplitude. The result of this research is to provide an immediate improvement in resolution loss and a possibility of realizing a still lower minimum resolving time when the ...
Contributing Partner: UNT Libraries Government Documents Department
Production research progress report, March 1--31, 1949

Production research progress report, March 1--31, 1949

Date: December 31, 1949
Creator: Payne, J.H. Jr.
Description: A study has been made of the time and temperature required to anneal Teflon and Fluorothene. It has been found that, by proper annealing, the strains my be removed and cold-flow prevented. The disk stopcocks prepared with annealed plastics have not developed leaks on standing. A description is given of the modified slug-dissolver heating unit which has been installed in the Bismuth-II Process Line. Work has been continued on the absorption spectra of bismuth in hydrochloric acid solutions. Two methods have been described for the interpretation of absorption spectra data. The transmission curve of the Evelyn colorimeter filters have been measured on the Cary recording spectrophotometer. The resulting curves should aid in the selection of the proper filter for a given calorimetric analyses. A brief outline for the proposed method of decontaminating platinum has been presented.
Contributing Partner: UNT Libraries Government Documents Department
Radioactive decontamination of metals by electropolishing

Radioactive decontamination of metals by electropolishing

Date: January 25, 1949
Creator: Brodbeck, R.M. & Schommer, G.R.
Description: Prior to April 1948 the generally accepted method of reducing the radioactive contamination of metal tools and laboratory apparatus was a series of rinses in aqua regia or various other concentrated acids. This method proved unsatisfactory for three reasons. (A) It was not a dependable method of removing activity. (B) It had a delecterious effect on tools in that it caused serious pitting, which resulted in weakened parts, and exposed a bare metal that was subject to very rapid corrosion. (C) Tools and apparatus once cleaned by this method could not readily be cleaned a second time. With the aforementioned limitations in mind, it became obvious that a new method was required. After considerable investigation into a electrochemical processes the present method was developed. Essentially, the new method is an electropolish bath to remove the activity lodged in the pores of the metal, and a ``follow-up`` chrome plate bath to render the surface impassive to corrosion.
Contributing Partner: UNT Libraries Government Documents Department
A high-speed low-sensitivity calorimeter for high activity (Ad Interim Report)

A high-speed low-sensitivity calorimeter for high activity (Ad Interim Report)

Date: March 2, 1949
Creator: Haring, M.M.
Description: This document is a March 1949 Ad Interim Report on the development of a high-speed, low-sensitivity calorimeter at the Mound Laboratory. This calorimeter is a zero-compensating, thermocouple, twin type. The outside diameter of the aluminum tubing was machined for a slip fit into the glass test tube. Prior to assembling in the test tube, an aluminum plug was pressed in it midway from the ends. A groove was also milled on the outside down to the plug, and a copper-constantan thermocouple was secured in the groove after assembly. A single layer of aluminum foil was used to reduce radiation effects, and stray air currents were excluded with a cotton plug. The two arms of the calorimeter were placed in a three-liter beaker filled with water. The constantan leads of the two thermocouples were soldered together to make them compensating. The copper leads were connected to a L & N potentiometer, and a L & N galvanometer was also used. The potentiometer-galvanometer circuit was so connected that before each reading of the EMF of the thermocouples, the thermal EMF in the circuit could be accounted for. The galvanometer was then mounted on a heavy brass plate. The data show that when ...
Contributing Partner: UNT Libraries Government Documents Department
Electronics accomplishment report

Electronics accomplishment report

Date: July 1, 1949
Creator: Gnagey, L.B.
Description: The following items of equipment have been completed: Two Scaler Multipliers, EO-18 and EO-338, undergoing test and adjustment. One Thyratron Heater Control for Scioto Laboratory. One Pilot model switch box for Group 16 hoods at Scioto Laboratory. One Pilot model patch box used as auxiliary to the present switch boxes. Installation of electronic equipment and sorting and cataloguing of stock at Scioto Laboratory has been started. The Y Section induction heaters have been installed electrically. With the present setup in the WD Building, it has been necessary to recycle all the solution which passes through the pH chamber on the clariflocculators. Sufficient tests have been run on the Berkeley Decimal scaler to indicate that, by using a pre-emplifier, it will be a satisfactory replacement for the scaler multiplier. Reworking of B-wall tubes has been held up pending the delivery of neon gas. Further investigations have been made on the frequency compensated constant voltage Sola transformers. Three automatic potential controllers have been modified in accordance with investigations of Group 10. The program of preventative maintenance on automatic potential controllers has resulted in a marked reduction of service calls and down-time for the operating group.
Contributing Partner: UNT Libraries Government Documents Department
Report on the biological research program for the period January 1, 1949--March 31, 1949

Report on the biological research program for the period January 1, 1949--March 31, 1949

Date: March 31, 1949
Creator: Svirbely, J.L.
Description: This document details the activities of the biological research program conducted by the Mound Laboratory during the first quarter of 1949.
Contributing Partner: UNT Libraries Government Documents Department
Electronics progress report, April 1--30, 1949

Electronics progress report, April 1--30, 1949

Date: December 31, 1949
Creator: Heyd, J.W. & Ohmart, P.E.
Description: Prospectus` of Band Pass Amplifiers for Proportional Counters and Instrumentation for the Study of the Electrodeposition Potential of Radioactive Elements have been submitted for review and approval. An error was found in calculations for the band pass amplifier discussed in Group 9 of the Electronics Progress Report,MLM-306, March 1--31, 1949, on the Cathode-Follower Probe. New calculations have been made and a band pass filter constructed to match the new values. Work on the cathode-follower circuit for coupling a Boron-wall tube to its linear amplifier indicated that the limit to the sharpness of a pulse which could be achieved was possibly caused by poor amplitude versus frequency response of the linear amplifier. To check this theory, modifications were made on an existing scaler which resulted in a frequency response flat up to 4.5 megacycles. Plans are being made to improve the amplitude versus frequency of the higher frequencies. The response curve shows a slightly rising characteristic at 4.5 megacycles and an attenuation at 7 megacycles. Construction of the rf generator has been resumed in an effort to deliver the finished product to Group 4 by approximately May 6, 1949. The meter circuit will measure relative rf output voltage instead of absolute ...
Contributing Partner: UNT Libraries Government Documents Department
The solution chemistry of polonium (Ad Interim Report)

The solution chemistry of polonium (Ad Interim Report)

Date: March 22, 1949
Creator: Haring, M.M.
Description: This document is a March 1949 Ad Interim Report from the Mound Laboratory on the solution chemistry of polonium. A consideration of the valences of the elements of the Group VI-A would indicate that the oxidation states of -2, 2, 4, and 6 might be expected for polonium. From the decrease in stability of the hydrides of these elements with increase in atomic number, one would expect that the compound H{sub 2} Po would be very unstable and that the oxidation state of -2 would not occur in solution. Furthermore, the stability of the oxidation state +6 as well as the stability of the highest oxidation state of a given element decreases as the atomic number increases in Group VI-A and Period VI respectively. For these reasons, the oxidation state +6 for polonium would be expected to occur only in a strongly oxidizing medium. The +4 state would be expected to be stable. The work discussed herein indicates that polonium exists as PoO{sup ++} in a nonoxidizing or reducing medium.
Contributing Partner: UNT Libraries Government Documents Department
Instrumental analysis progress report, June 1--30, 1949

Instrumental analysis progress report, June 1--30, 1949

Date: December 31, 1949
Creator: Timma, D.L.
Description: Several bismuth compounds have been submitted by E. Orban for examination by x-ray diffraction. The sample of polonium in contact with platinum mentioned in the May progress report was received and identified tentatively from its x-ray diffraction pattern as PtPo{sub 2}. Calibration of the Perkin-Elmer infrared spectrophotometer has been completed and a preliminary study of the infrared absorption of NiCO{sub 4} made. Data showing the spectral purity obtainable on three ultraviolet-visible spectrophotometers have been completed. The emission spectrum of a sample of volatile impurity from the operations process has been obtained.
Contributing Partner: UNT Libraries Government Documents Department
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