J.M. Cameron

Complete Set of Deuteron Analyzing Powers in Deuteron-Proton Elastic Scattering: Measurement and Realistic Potential Predictions

Tensor analyzing powersiT11,T20,T21 andT22, have been measured for deuteron laboratory energiesElabd=75, 85, 95, 106, 119, 131, 144, 156, 172, and 187 MeV. The data are compared to rigorous Faddeev calculations with realistic nucleon-nucleon potentials. A generally good description of the data at all energies is obtained.

The design and calibration of the AHEAD deuteron polarimeter for 120 < Ed < 250 MeV

A new type of deuteron polarimeter to work in the energy range 120 < Ed < 250 MeV has been designed, constructed, and calibrated. The figure of merit (√ϵTkq) has been determined for various polarization components from the calibration data.

Measurement of the polarization of a pulsed electron beam with a Møller polarimeter in the coincidence mode

Abstract The Moller polarimeter at the Bates Linear Accelerator Center was used to measure the polarization of an 868-MeV electron beam with a duty cycle of 0.8%. Longitudinally polarized electrons in the beam were scattered from polarized atomic electrons in an Feue5f8Co foil, and the helicity-dependent scattering asymmetry was measured by detecting both electrons in coincidence with a pair of Cherenkov counters located symmetrically on either side of the beam. From the measured asymmetry, the beam polarization was inferred to be (42.4 ± 1.7 ± 1.2)%, where the first uncertainty is statistical and the second is systematic.

Production of a tagged medium resolution neutron beam

Abstract Dissociation of 260 MeV deuterons in natural C and Cu targets has been studied using an internal deuteron beam in the Indiana University Cyclotron Facility Cooler Ring. Angular distributions and energy correlations are reported for both the (d, pn) and (d, pX) reactions, and implications for using the coincidence reaction for producing a tagged, medium resolution neutron beam are discussed.

Calibration of a neutron polarimeter to measure the electric form factor of the neutron

We measured the analyzing power and the efficiency of a new neutron polarimeter that was designed to measure G/sub E//sup n/, the neutron electric form factor. The polarimeter calibration was performed as experiment E377 at the Indiana University Cyclotron Facility (IUCF) with the /sup 14/C(p/spl I.oarr/,n/spl I.oarr/)/sup 14/N reaction at proton beam energies of 124.0, 164.6, and 199.7 MeV without any shielding material ahead of the polarimeter; in addition, at 164.6 MeV we measured the analyzing power with 10 cm of lead, sandwiched between 3.5-cm iron plates, ahead of the polarimeter.

Status of Bates experiment 85‐05: The electric form factor of the neutron from the d(e↘,e’n↘)p reaction

The Bates E85‐05 Collaboration measured the polarization of the neutron in the d(e↘,en↘)p reaction in the quasifree region with the objective of extracting the electric form factor of the neutron. Electron‐neutron coincidence spectra were obtained during 567 μA‐hours of integrated beam. We succeeded in operating a Mo/ller scattering polarimeter in the coincidence mode with a low‐duty factor accelerator in order to measure the polarization of the electron beam.

Present and future use of stored electron cooled beams at the Indiana University cyclotron facility

A brief outline is given of the present program using stored electron cooled beams at the Indiana Cooler. The possibility of extending these techniques to higher energies is discussed.

Neutron electromagnetic form factors

Nucleon form factors provide fundamental input for nuclear structure and quark models. Current knowledge of neutron form factors, particularly the electric form factor of the neutron, is insufficient to meet these needs. Developments of high‐duty‐factor accelerators and polarization‐transfer techniques permit new experiments that promise results with small sensitivities to nuclear models. We review the current status of the field, our own work at the MIT/Bates linear accelerator, and future experimental efforts.

Neutron detection efficiency for the measurement of the 2H(e,′en) 1H cross section

We report a measurement of the neutron detection efficiency for an array of neutron detectors behind a lead-steel wall consisting of 10.16 cm thick lead bricks sandwiched between 3.18 cm steel plates. The neutron detection efficiency was obtained from the ratio of coincidence to single-arm proton cross sections using the gamma+{sup 2}{sub 1}H -->p+n reaction. Knowledge of the neutron detection efficiency was necessary to extract the cross section for the exclusive {sup 2}H(e,en){sup 1}H reaction, which we used to obtain the elastic magnetic form factor G{sup n}{sub M} of the neutron. The measurements for three different neutron energies were carried out at the MIT-Bates Linear Accelerator Center with an incident electron beam energy of 254 MeV.

Tensor Polarization Measurements of the Recoil Deuterons in Elastic Electron-Deuteron Scattering

The tensor polarization t 20 of the recoil deuteron in elastic e-d scattering has been measured for three values of four-momentum transfer, q = 3.78, 4.22, and 4.62 fm-1. The results have been used to separate the charge monopole and charge quadrupole form factors of the deuteron and to locate the first node in the charge monopole form factor at q = 4.39 ± 0.16 fm-1. The extracted t 20 values are compared with several theoretical predictions.