The main emphasis during the past year has been on analyzing and publishing results and the preparation for the impending start-up of the newly modified Nevis cyclotron. Papers on the separated isotopes of Yb and W have been submitted to the Physical Review. The published results on Er confirm Dyson's theory of level spacing systematics. The total cross section, resonance parameters and spin-parity values of Na below 300 keV have been submitted for publication. A report on the evaluation of the T's of U 238 has been distributed. We now have extensive results on the Er isotopes, 232 U, 152 > 15lt Sm, 151 , 153 Eu, Fe, La, In, Ta, F, Mg, Al, S, CI, K and Ca. A paper on the precision measurement of the 2200 m/sec neutron-proton capture cross section has been submitted for publication. The background for fission measurements has been extensively analyzed and modifications to the neutron source of the Nevis cyclotron will be made for the next run. New methods of analyzing low count rate data have been developed to eliminate observation of spurious levels. The captive cross sections of thulium and rhodium have been analyzed and the results reported.-NOTICEThis report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Atomic Energy Commission, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. EtfSTRIBUTION OF THIS DOCUMENT IS UNLIMITED DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. During the report period, our main emphasis has been on analyzing and publishing data, and the preparation for the impending startup of the newly modified Nevis cyclotron. A number of major papers and reports on our results have been published or submitted for publication. Papers on the neutron reso...

During 1977 a six week run was performed at ORELA using the new data acquisition system based on the PDP-11. Coincident double energy fission fragments were measured as a function of neutron time-of-flight for 229 Th, 235 U and 239 Pu. Data was also obtained in the thermal energy region. Extensive results are reported on the 1976 229 Th measurements with 2 families of widely differing fission widths determined. Earlier results on the variation of the ratio of symmetric to asymmetric mass division on 239 Pu fission were confirmed. Variations in the total kinetic energies of 235TJ resonances have been seen. An experiment using 252 Cf and measuring the energy of two coincident fission fragments and the time-of-flight of one of them was started. Work on the adaption of the code MULTI to the Columbia University computer was continued.

During 1975 -76 several experiments were performed at ORELA. The single fragment kinetic energy measurements on 235 U were continued and a run on 229 Th was added. Coincident double energy measurements were started both on 235 U and 229 Th. Mass and total kinetic energy distributions have been calculated. The data which have been analyzed,up to date show similar, but more complex effects than reported earlier. Cross Sections of 229 Th have been determined and many new levels discovered. A new computer program has been written to analyze the saturated resonances in capture cross section measurements. Calculations on the bias introduced in fission cross section measurements using, ionization chambers have been concluded. The calculational program started last year with the objective of determining the contribution of neutron scattering by the iron pole pieces of the Nevis synchrocyclotron to the observed backgrounds has been continued. "This report was prepared as an account of Government^sponsored work. Neither the United States, nor the Energy Research and Development Administration, nor any person acting on behalf of the Administration:A. Makes any warranty or representation, expressed or implied, with respect to the accuracy, completeness., or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of, any information, apparatus, method, or process disclosed in this report.As used in the above, 'person acting on behalf of the Administration' includes any employee or contractor of the Administration, or employee of such contractor, to the extent that such employee or contractor of the Administration, or employee of such contractor prepares, disseminates, or provides access toV and information pursuant to his employment or contract with the Administration, or his employment with such contractor."

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The main emphasis during the past year has been on analyzing and publishing results and the preparation for the impending start-up of the newly modified Nevis cyclotron. Papers on the separated isotopes of Yb and W have been submitted to the Physical Review. The published results on Er confirm Dyson's theory of level spacing systematics. The total cross section, resonance parameters and spin-parity values of Na below 300 keV have been submitted for publication. A report on the evaluation of the T's of U 238 has been distributed. We now have extensive results on the Er isotopes, 232 U, 152 > 15lt Sm, 151 , 153 Eu, Fe, La, In, Ta, F, Mg, Al, S, CI, K and Ca. A paper on the precision measurement of the 2200 m/sec neutron-proton capture cross section has been submitted for publication. The background for fission measurements has been extensively analyzed and modifications to the neutron source of the Nevis cyclotron will be made for the next run. New methods of analyzing low count rate data have been developed to eliminate observation of spurious levels. The captive cross sections of thulium and rhodium have been analyzed and the results reported.-NOTICEThis report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Atomic Energy Commission, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. EtfSTRIBUTION OF THIS DOCUMENT IS UNLIMITED DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. During the report period, our main emphasis has been on analyzing and publishing data, and the preparation for the impending startup of the newly modified Nevis cyclotron. A number of major papers and reports on our results have been published or submitted for publication. Papers on the neutron reso...