18 Matching Results

Search Results

Advanced search parameters have been applied.

Absolute polarization standards at medium and high energies. [200 to 900 MeV]

Description: Although measurement of a polarization asymmetry is rather easy, the normalization of the measurement to obtain the analyzing power requires an absolute knowledge of the beam polarization or comparison with a known standard analyzing power. Such calibration standards can be hard to find. This paper concentrates on medium and higher energies, and divides the techniques into four categories: double scattering, polarized target methods, polarized source methods, and theoretical methods. Secondary standards are also discussed, and earlier data are assessed. 52 references, 6 figures. (RWR)
Date: January 1, 1980
Creator: McNaughton, M.W.
Partner: UNT Libraries Government Documents Department

LAMPF beam line polarimeters

Description: This report describes the beam line polarimeters that are used in the primary p/sup -/ beams at LAMPF to monitor and measure the polarization of the beam. The devices are secondary standards of polarization and are calibrated primarily by the ion source quench ratio technique. Some independent checks of this technique are discussed.
Date: April 1, 1980
Creator: McNaughton, M.W.
Partner: UNT Libraries Government Documents Department

Polarization research and facilities at LAMPF

Description: In summary, facilities exist for spin correlation and spin transfer measurements from 300 to 800 MeV with all (N,S,L) spin directions, and an energetic program is being pursued in several beam lines simultaneously. Elastic pp measurements at a few energies are making good progress but polarized neutron experiments are lagging. The problem of understanding the inelastic reactions has scarcely begun.
Date: January 1, 1981
Creator: McNaughton, M.W.
Partner: UNT Libraries Government Documents Department

Nucleon-nucleon measurements at LAMPF

Description: The first goal of the nucleon-nucleon groups at LAMPF is the complete determination of the isospin 0 and 1 elastic scattering amplitudes to 5% from 500 to 800 MeV. When previous data are combined with the recent data reported here, these amplitudes become well determined near 500 and 800 MeV. Measurements scheduled for 1991 should complete the measurements within this energy range. 12 refs., 1 fig., 1 tab.
Date: January 1, 1991
Creator: McNaughton, M.W.
Partner: UNT Libraries Government Documents Department

LAMPF Nucleon-Nucleon Program

Description: NN activities at LAMPF are summarized. Measurements with p+p are now focusing on inelastic spin transfer and spin correlations. There should be good coverage of np spin correlations by 1986. Additional facilities are outlined for polarized beam nucleon and nuclear physics. 15 references.
Date: January 1, 1984
Creator: van Dyck, O.B. & McNaughton, M.W.
Partner: UNT Libraries Government Documents Department

Need for an intense polarized source at LAMPF. Report on a workshop held at Los Alamos, November 9, 1983

Description: We report on a workshop to consider the need for an intense polarized source at LAMPF. The primary justification for such a source comes from the nucleon-nucleon program; neutron-proton scattering is seriously underdetermined and cannot be satisfactorily completed without such an intense source. Further justification comes from nuclear (vector n,p) and (vector p, vector n) reactions, as well as from traditional nuclear physics at the LAMPF high resolution spectrometer. We recommend that a source capable of providing a few ..mu..A beam on target be built as soon as possible.
Date: April 1, 1984
Creator: McNaughton, M.W.; Silbar, R.R. & van Dyck, O.B.
Partner: UNT Libraries Government Documents Department

Radionuclide Concentration in Soils and Vegetation at Low-Level Radioactive Waste Disposal Area G during 2005

Description: Soil samples were collected at 15 locations and unwashed overstory and understory vegetation samples were collected from up to nine locations within and around the perimeter of Area G, the primary disposal facility for low-level radioactive solid waste at Los Alamos National Laboratory (LANL). Soil and plant samples were also collected from the proposed expansion area west of Area G for the purpose of gaining preoperational baseline data. Soil and plant samples were analyzed for radionuclides that have shown a history of detection in past years; these included {sup 3}H, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, and {sup 238}U for soils and {sup 3}H, {sup 238}Pu, and {sup 239,240}Pu for plants. As in previous years, the highest levels of {sup 3}H in soils and vegetation were detected at the south portion of Area G near the {sup 3}H shafts; whereas, the highest concentrations of the Pu isotopes were detected in the northern and northeastern portions near the pads for transuranic waste. All concentrations of radionuclides in soils and vegetation, however, were still very low (pCi range) and far below LANL screening levels and regulatory standards.
Date: October 1, 2005
Creator: Fresquez, P.R.; McNaughton, M.W. & Winch, M.J.
Partner: UNT Libraries Government Documents Department

Nucleon-nucleon data

Description: This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). This work completes the determination of the nucleon-nucleon (NN) scattering amplitudes from 485 to 800 MeV. The data set is completed by the publication of two papers. These new data have a precision better than 1% and an absolute accuracy about 1%, which is generally an order of magnitude better than previous data. The NN data set is now complete and consistent. The set of spin-dependent NN-scattering amplitudes is now well determined up to 800 MeV.
Date: October 1, 1997
Creator: McNaughton, M.W.; Gulmez, E. & Whitten, C.A.
Partner: UNT Libraries Government Documents Department

Performance of the LAMPF optically pumped polarized ion source

Description: In 1992, the LAMPF optically pumped polarized ion source (OPPIS) was used in experiments demanding a wide range of currents and polarizations. OPPIS was operated in different configurations to meet the differing current and polarization requirements for each experiment. We describe methods used to increase beam polarization at the expense of current for experiments that were count rate limited. OPPIS can be operated at 50 [mu]A, giving 56% polarization, 25 [mu]A with 65% polarization, or 2 [mu]A with 77% polarization. The source reliability in 1992 was excellent, easily exceeding 95%. Contributions to experimental systematic errors made by the source were measured in 1992. We speculate about further improvements that can be made to OPPIS.
Date: January 1, 1993
Creator: York, R.L.; Tupa, D.; Swenson, D.R.; McNaughton, M.W. & vanDyck, O.B.
Partner: UNT Libraries Government Documents Department

Performance of the LAMPF optically pumped polarized ion source

Description: In 1992, the LAMPF optically pumped polarized ion source (OPPIS) was used in experiments demanding a wide range of currents and polarizations. OPPIS was operated in different configurations to meet the differing current and polarization requirements for each experiment. We describe methods used to increase beam polarization at the expense of current for experiments that were count rate limited. OPPIS can be operated at 50 {mu}A, giving 56% polarization, 25 {mu}A with 65% polarization, or 2 {mu}A with 77% polarization. The source reliability in 1992 was excellent, easily exceeding 95%. Contributions to experimental systematic errors made by the source were measured in 1992. We speculate about further improvements that can be made to OPPIS.
Date: July 1, 1993
Creator: York, R. L.; Tupa, D.; Swenson, D. R.; McNaughton, M. W. & vanDyck, O. B.
Partner: UNT Libraries Government Documents Department

Emergency Medical Rescue in a Radiation Environment

Description: Previous experience with emergency medical rescues in the presence of radiation or contamination indicates that the training provided to emergency responders is not always appropriate. A new course developed at Los Alamos includes specific procedures for emergency response in a variety of radiological conditions.
Date: September 14, 1999
Creator: Briesmeister, L.; Ellington, Y.; Hollis, R.; Kunzman, J.; McNaughton, M.; Ramsey, G. et al.
Partner: UNT Libraries Government Documents Department

Polarimeter for protons between 300 and 800 MeV

Description: A polarimeter for protons between 300 and 800 MeV has been constructed. It uses a carbon block analyzer of variable thickness and 6 drift chambers for particle tracking.
Date: January 1, 1980
Creator: Ransome, R.D.; Hollas, C.L.; Greene, S.J.; Bonner, B.E.; McNaughton, M.W.; Morris, C.L. et al.
Partner: UNT Libraries Government Documents Department

Spin rotation parameters D/sub NN/, D/sub SL/, D/sub SS/, D/sub LS/, D/sub LL/ and P for vector pd. -->. vector pd elastic scattering at 500 and 800 MeV

Description: The measurement of the spin rotation parameters D/sub NN/, D/sub SL/, D/sub SS/, D/sub LS/ and D/sub LL/ for vector pd ..-->.. vector pd elastic scattering can be used to determine the depolarization parameters Do, Dx, Dy and Dz. Calculation by the Glauber model shows that the single scattering contributions to Dx and Dz depend only on the double spin flip components of the NN amplitude. The double scattering contributions to Dx and Dz are also sensitive to these amplitudes. So Dx and Dz are of considerable interest for providing selective information about the double spin flip components. Moreover, since the deuteron is the nucleus with the simplest bound state, the effects of the non-eikonal and non-relativistic approximations in the Glauber model can be tested. In this work we plan to use the well known amplitudes at 500 MeV to check the Glauber calculation. Then using this model we hope to extract the amplitudes at 800 MeV, which are not so well determined.
Date: January 1, 1983
Creator: Sun, T.; Bonner, B.E.; McNaughton, M.W.; Van Dyck, O.B.; Weston, G.S.; Aas, B. et al.
Partner: UNT Libraries Government Documents Department

First measurement of K/sub NN/ in the reaction vector pp. -->. vector d. pi. /sup +/ at 800 MeV

Description: Recent controversy over the existence of exotic strangeness-zero resonances in the two nucleon system has emphasized the fact that this system presents an inherently multi-channel problem just above pion production threshold. Exotic two-nucleon states, if they exist, are certainly very inelastic. This leads to the conclusion that measurements of pion production channels to roughly the same extent and accuracy as measurements of nucleon-nucleon elastic scattering are necessary for fuller understanding of the two nucleon system. The results presented should provide valuable input to these multi-channel models needed to understand the two nucleon system. 6 references.
Date: January 1, 1983
Creator: Turpin, S.E.; Bonner, B.E.; van Dyck, O.B.; McNaughton, M.W.; Cremans, D.J.; Hollas, C.L. et al.
Partner: UNT Libraries Government Documents Department

Novel technique for measuring the vector polarization of a deuteron

Description: The usual method of double scattering that is employed for measuring the vector polarization (P = 2/..sqrt..3 it/sub 11/) of final state deuterons in a reaction is to use the appreciable analyzing power available for certain angular regions of elastic scattering or deuteron initiated reactions. For increasing deuteron energies the cross section and/or analyzing power for such processes generally decreases, thus limiting the utility of this technique at intermediate energies. We recently developed a method for measuring it/sub 11/ and demonstrated its validity for deuterons in the energy range 500 to 600 MeV. The technique should be applicable for deuteron energies in the range 400 MeV to a few GeV. A brief description of the technique is given.
Date: January 1, 1983
Creator: Bonner, B.E.; McNaughton, M.W.; van Dyck, O.B.; Turpin, S.E.; Hollas, C.L.; Cremans, D.J. et al.
Partner: UNT Libraries Government Documents Department

D/sub SS/, D/sub LS/, D/sub LL/ and P for pp elastic scattering at 699 and 750 MeV/sup +/

Description: The pp elastic scattering amplitudes have been extensively investigated at intermediate energies over the past several years. Sufficient data exist for the extraction of the amplitudes at 548 and 445 MeV and at 800 and 647 MeV. Few observables have been measured at energies between 650 and 800 MeV. To provide data in this energy region we have made measurements of the depolariztion parameters D/sub SS/, D/sub LS/ and D/sub LL/ and the polarization parameter P at center of mass angles between 40/sup 0/ and 120/sup 0/ at 699 and 750 MeV.
Date: January 1, 1983
Creator: Cremans, D.J.; Hollas, C.L.; McNaughton, K.H.; Riley, P.J.; Rodebaugh, R.F.; Xu, S. et al.
Partner: UNT Libraries Government Documents Department

Polarization observables D/sub NN/, P and A for vector pp. -->. vector p. pi. /sup +/n at 800 MeV

Description: In conjunction with a vector polarization transfer measurement in the vector pp ..-->.. vector d..pi../sup +/ reaction, we also obtained data on polarization observables for vector pp ..-->.. vector p..pi../sup +/n at 800 MeV incident proton energy. Scattered protons were detected in a spectrometer at angles from 5/sup 0/ to 11/sup 0/. Pions were detected in coincidence at angles 80/sup 0/ to 130/sup 0/. The proton momentum range covered was from 800 to 1300 MeV/c. The prominent peak observed near 1150 MeV/c in the proton spectrum is a reflection of ..delta../sup + +/ production at center of mass angles from 0/sup 0/ to 30/sup 0/. Regions of the spectrum corresponding to ..delta../sup + +/ production at backward THETA/sub cm/ angles and to the /sup 1/S/sub 0/ np final state interaction fall below the momentum acceptance limit for the spectrometer setting used in the present measurements. The events were binned into five proton momentum bins for the determination of the polarization observables D/sub NN/, P, and A.
Date: January 1, 1983
Creator: Bonner, B.E.; McNaughton, M.W.; van Dyck, O.B.; Turpin, S.E.; Cremans, D.J.; Hollas, C.L. et al.
Partner: UNT Libraries Government Documents Department