The two-body photodisintegration of He-3 has been investigated using tagged photons with energies from 14-31 MeV at MAX-lab in Lund, Sweden. The two-body breakup channel was unambiguously identified by the (nonsimultaneous) detection of both protons and deuterons. This approach was made feasible by the overdetermined kinematic situation afforded by the tagged-photon technique. Proton-and deuteron-energy spectra were measured using four silicon surface-barrier detector telescopes located at a laboratory angle of 90 degrees with respect to the incident photon-beam direction. Average statistical and systematic uncertainties of 5.7% and 6.6% in the differential cross section were obtained for 11 photon-energy bins with an average width of 1.2 MeV. The results are compared to previous experimental data measured at comparable photon energies as well as to the results of two recent Faddeev calculations which employ realistic potential models and take into account three-nucleon forces and final-state interactions. Both the accuracy and precision of the present data are improved over those obtained in the previous measurements. The data are in good agreement with most of the previous results, and favor the inclusion of three-nucleon forces in the calculations.

A broad excited state was observed in 6-He with energy E_x = 5 +/- 1 MeV and width Gamma = 3 +/- 1 MeV, following the reaction Li-7(gamma,p)He-6. The state is consistent with a number of broad resonances predicted by recent cluster model calculations. The well-established reaction mechanism, combined with a simple and transparent analysis procedure confers considerable validity to this observation.

A combined Bragg-PPAC ionization detector has been developed for registration and identification of light charged particles from photonuclear reactions at tagged photon beams. The detector is described and also its performance, which was obtained in a test experiment at the tagged photon beam.

A broad range tagging spectrometer together with a new beam transport system for photonuclear experiments at the MAX-laboratory in Lund is described. The spectrometer consists of a quadrupole followed by an Elbek-type dipole and has a large momentum acceptance. It can produce both polarized and unpolarized tagged photons in the energy range 10–80 MeV with an energy resolution of about 300 keV.

The (gamma,d) and (gamma,t) reactions on Li-6 were studied at average (tagged) photon energies of 59 and 75 MeV. Differential cross sections were obtained at five different angles (30 degrees less than or equal to theta(lab) less than or equal to 150 degrees), from which the integrated-over-angle cross sections for the d(0) and t(0) channels were determined. The experimental results are discussed in terms of a cluster model calculation.

The Li-6(gamma,p) reaction was measured at average tagged photon energies of [E(gamma)] = 59 and 75 MeV. Protons were detected at 5 different angles between 30 degrees and 150 degrees. Most of the observed strength is apparently due to the three-body breakup channels. In particular the semi-inclusive (gamma,p(n)) and (gamma,p(t)) channels are discussed.

The 6Li(γ,p) reaction was measured at average tagged photon energies of 〈Eγ〉 = 59 and 75 MeV. Protons were detected at 5 different angles between 30° and 150°. Most of the observed strength is apparently due to the three-body breakup channels. In particular the semi-inclusive (γ,p(n)) and (γ,p(t)) channels are discussed.

The results of a study of the 6Li(γ, cc) (c, c:́ charged particle) reaction with the tagged-photon technique are presented. It is shown that the (γ, pt) reaction can be understood within the framework of a semi-phenomenological quasi-alpha reaction model. The total (γ, pt) cross section is found to be larger than the 6Li(γ, pn)α cross section at the same photon energy. No evidence is found for a three-body absorption mechanism, but the possible role of final-state interactions in the (γ, pd) reaction is outlined.

The tagged photon technique has been used to measure the excitation energy spectra resulting from the (gamma, p) reaction in Li-6 and C-12 at 90 degrees for incident photon energies around 61 and 77 MeV. Strong evidence is found for the quasideuteron absorption mechanism, not only in the high excitation energy regions, but also in bound states. Furthermore, for the C-12(gamma, p) reaction the photon seems to be absorbed on pn-pairs in both T = 0 and T = 1 states.

A new, improved method to define the random particle energy spectrum in tagged photon experiments is described. This procedure yields the random spectrum with very good statistical accuracy, and can be applied when no hard coincidence with the focal plane is required in order to accept events.

The polarizabilities of nucleons imbedded in 12C and 16O nuclei are measured via Compton scattering of 61 and 77 MeV photons, leading to αN = (11.5±0.8±2.1) × 10−4fm3 and βN = (2.5∓0.8∓2.1) × 10−4fm3 in close agreement with the free-nucleon values.

A description is given of the photon tagging facility at the MAX accelerator system in Lund for use in photonuclear experiments in the energy region between the giant delta resonances. The system enables experiments with high-energy resolution, 300 keV at 60 MeV photons, and a tagged rate of 5 × 106/sMeV.

The coincident electrofission (e,e'f) cross sections of $^{233,238}\mathrm{U}$ were measured in the excitation range 150--550 MeV. The probability of fission was found to be near unity in the delta resonance region (250--550 MeV), but less than unity in the quasifree scattering region (150--250 MeV). The data are analyzed with a model based on the quasifree and delta reaction mechanisms. An excitation energy of 25 MeV is found for the residual nucleus in the quasifree region and over 40 MeV in the delta region.

Spectra of protons and deuterons emitted in the photodisintegration of $^{27}\mathrm{Al}$ and $^{\mathrm{nat}}\mathrm{Ca}$ have been measured with the tagged photon technique. The experimental data are compared to the results of calculations using the hybrid model for pre-equilibrium reactions. For the first time it is possible to determine the relevant initial doorway configuration, i.e., a 2p-1h doorway, appropriate for quasideuteron absorption.

The reaction6Li (γ, d) with Eγ around 60 MeV has been investigated with monoenergetic photons using a Si-Ge ΔE-E telescope, allowing accurate identification of deuterons with good energy resolution. A strict obedience of the isospin selection rule for E1 absorption, i.e. ΔT=1, is observed for the ground state transition.

Excitation-energy spectra resulting from the $^{12}\mathrm{C}$, $^{16}\mathrm{O}$, and $^{40}\mathrm{Ca}$(\ensuremath{\gamma},p) reactions at 90\ifmmode^\circ\else\textdegree\fi{} have been measured with tagged photons of about 61 and 77 MeV. Decay to several discrete states is discussed. Evidence is shown for an absorption process where the photon interacts with a T=1 proton-neutron pair, instead of the T=0 p-n pair implicit in the quasideuteron model.