Purpose: To quantify the radiological consequences of a release of PET isotopes in gaseous form to the environment, in an urban setting. Methods: The worst case scenario is identified heuristically and an analytical treatment of the worst case scenario is made using ideas from turbulent hydrodynamics to calculate the minimum dispersion of a cloud of PET isotopes (11C, 13N, 14O, 15O & 18F) in the atmosphere emerging from a ventilation stack, either from the accelerator vault or from a hot cell. A Gaussian plume model is used to calculate the average radiological consequence. Results: It is shown that 11C production has the worst radiological consequences for an atmospheric release. Whole body and equivalent doses are calculated using Gaussian and uniform radioisotope concentration profiles in the atmosphere for skin, inhalation and external annihilation gamma fields. It is found that the worst case is when there is an atmospheric inversion present, and when the ambient temperature is higher than the stack exhaust temperature as this generates negative buoyancy. The parameters of this model are the stack exhaust velocity, temperature and diameter, the ambient temperature, the released activity, the half‐life, and the mean positron range, but not the release height. It is shown that for the Gaussian plume model the mean wind speed and release height are important as well as the release time. Conclusions: The design features of the ventilation system of a PET facility which can simply and effectively control the radiological consequences of an atmospheric release are identified. The impact of these results on current regulatory thinking on PET isotope production facility design goals and permissible releases in Canada is discussed.

The neutrino flux produced by the spallation neutron source ISIS at the position of the KARMEN neutrino experiment is calculated to an accuracy of 6.7%. Contributions from the spallation and μSR targets to the νμ, νe, and ν¯μ fluxes, due to π+ and μ+ decay at rest, are evaluated. Results are presented in terms of neutrinos per proton for incident proton beams of 750 and 800 MeV. The contamination of ν¯e, from the π− decay-in-flight and μ− decay-at-rest chain, is found to be 0.06% with an accuracy of 12%.

The KARMEN experiment at the pulsed neutron facility ISIS is investigating neutrino-nucleus reactions and neutrino oscillations. In this paper we present cross sections for neutrino induced charged and neutral current reactions on C-12. These results allow a precision test of the standard model of weak interaction by imposing new limits on the neutral current isovector axial vector coupling strength beta(A), the strength parameter rho measuring the universality of W+/- and Z(0) coupling in the low energy regime and by investigating the Lorentz, structure of muon decay. Neutrino oscillations (v) over bar (mu)-->(v) over bar (e) are investigated in the appearance mode by looking for p((v) over bar (e), e(+))n reactions. An analysis of 3 years running time with the KARMEN2 setup reveals no indication of an oscillation signal excluding most parts of the LSND oscillation evidence.

The KARMEN experiment at the pulsed spallation neutron facility ISIS uses the beam stop neutrinos vμ, ve and v̄μ from π+ and μ+ decay at rest to search for neutrino oscillations in the appearance modes vμ → ve and v̄μ → v̄e. A high resolution 56 ton liquid scintillation calorimeter located at a mean distance of 17.5 m from the proton beam stop allows identification of ve and v̄e with spectroscopic quality. We report the status of our search for neutrino oscillations after four years of running. No positive evidence for neutrino oscillations has been observed in both appearance channels. The 90 % CL limits of this experiment exclude mixing angles sin2 2 Θ ≥ 0.0062 in the v̄μ → v̄e channel and sin2 2 Θ ≥ 0.048 in the vμ → ve channel for the region Δm2 > 1 eV2

The KARMEN experiment at the pulsed spallation neutron facility ISIS uses the beam stop neutrinos nu(mu), nu(e) and <(nu)over bar>(mu) from pi(+) and mu(+) decay at rest to search for neutrino oscillations in the appearance modes nu(mu) --> nu(e) and <(nu)over bar>(mu) --> <(nu)over bar>(e). A high resolution 56 ton liquid scintillation calorimeter located at a mean distance of 17.5 m from the proton beam stop allows identification of nu(e) and <(nu)over bar>(e) with spectroscopic quality. We report the status of our search for neutrino oscillations after four years of running. No positive evidence for neutrino oscillations has been observed in both appearance channels. The 90 % CL Limits of this experiment exclude mixing angles sin(2)2 Theta greater than or equal to 0.0062 in the <(nu)over bar>(mu) --> <(nu)over bar>(e) channel and sin(2)2 Theta greater than or equal to 0.048 in the nu(mu) --> nu(e) channel for the region Delta m(2) > 1 eV(2)

The KARMEN experiment at the pulsed spallation neutron facility ISIS studies the charged and neutral current reactions C-12 (nu(e),e(-)) N-12 and C-12 (nu,nu') C-12* (1(+)1) in the astrophysical important energy range up to 50 MeV. Neutrinos are detected by a 56 ton high resolution Liquid scintillation calorimeter with spectroscopic quality. Efficient background rejection results in clear neutrino signatures and allows reliable cross section measurements down to 10(-42) cm(2) We present cross section results for nu-induced reactions on carbon with special emphasis on their implications for neutrino astrophysics and weak nuclear formfactors and report a new flux-independent test of the equality of the couplings of nu(e) and <(nu)over bar>(mu) to the weak neutral current at low energies.

The KARMEN experiment at the pulsed neutron facility ISIS is investigating neutrino properties and interactions by measuring neutrino-induced charged current (CC) 12C(νe,e−)12N reactions and, for the first time, neutral current (NC) 12C(ν,ν′) 12C∗ excitations of nuclei. We present cross section results for these reactions in the energy range of beam dump neutrinos Eν ≤ 52.8MeV with emphasis on weak nuclear form factors and μ - e - universality of neutral currents.

Neutrinos from pion and muon decay at rest offer unique possibilities for precision tests of the Standard Model at low energies. With typical neutrino interaction rates in this energy domain being only of the order of 10−42 cm2 high quality detection methods are required. The spectroscopic quality of neutrino identification in the KARMEN experiment at the pulsed spallation source ISIS allows a high sensitivity search for neutrino oscillations in the appearance channels νμ→νρ and νμ→νρ. In addition, neutrino spectroscopy is used to look for non-standard (scalar and tensor) amplitudes in weak charged currents, while conservation laws are tested by a search for lepton number violating muon and pion decays allowed in Left - Right symmetric models. We present the results of the KARMEN experiment with regard to tests of the Standard Model obtained from the first three years of data taking.

The KARMEN (KArlsruhe Rutherford intermediate Energy Neutrino) experiment identifies and analyses nuclear reactions induced by ISIS beam-dump neutrinos in a segmented liquid scintillation detector. A pulsed laser beam, distributed and transformed through a network of light guides and scintillation light splitters, is used to monitor calorimetric and timing properties of the 512 central detector segments. This report describes the setup and applications of the laser calibration monitor at KARMEN. Data obtained with the laser system concern energy- and position resolutions, the linearity and offset of energy measurements, the correction of timing signals for energy-dependent walk effects, and the determination of absolute event times.

KARMEN denotes an experimental program of neutrino physics using a pulsed source of neutrinos νμ, νeandνμ with energies up to 52.8 MeV and a 56 t scintillation calorimeter. Major physics aims are the measurement of charged current (CC) as well as neutral current (NC) neutrino nucleus interactions on 12C with their implications for specific weak couplings, nuclear formfactors, μ-e universality and the search for neutrino oscillations νμ → νeandνeandνμ → νe. We present the results of the KARMEN experiment from its first two years of data taking.

We discuss the sensitivity of magnetic transitions in nuclei like 12C, to a small neutrino magnetic moment, and its implications for current and future experiments. We also point out that coherent neutrino-nuclear elastic scattering in low-temperature detectors, might improve the present laboratory bounds on the neutrino magnetic moment by an order of magnitude.

Using an instrumented proton beam stop, consisting of copper, lead, and water, the distribution and number of stopped π+ per incident proton was measured for proton energies of 716, 766, and 797 MeV. The decay sequence of stopped pions and muons produce a well defined spectrum of νe, νμandνμ. The present experiment determines the neutrino production f stopped π+ decay by measuring the ratio of stopping pions per incident proton to an uncertainty of 8%.

Energy spectra and differential cross sections have been obtained for the charge exchange reaction ${(}^{3}$H${,}^{3}$He) on targets of $^{30}$,28Si and $^{26}\mathrm{Mg}$ at an incident energy of 36 MeV. Previously unobserved energy levels of $^{30}\mathrm{Al}$ and $^{26}\mathrm{Na}$ are reported and compared to shell model predictions. Microscopic form factors based on the M3Y effective nucleon-nucleon interaction are used in distorted-wave Born approximation codes to fit the data. The sensitivity of the model to input parameters is discussed and some spin assignments made. Coupled channels calculations are performed to fit the two-step contributions to the data via sequential one-nucleon transfers.

36 MeV triton elastic scattering data have been obtained for targets of 30Si, 28Si, 26Mg, 16O and 12C. These data are analysed in terms of a conventional phenomenological optical model and double-folding optical model.

Data for the 28Si(7Li,7Be)28Al reaction at 72 MeV and for the 26Mg(7Li,7Be)26Na reaction at 88 MeV are presented together with one-step DWBA calculations using microscopic form factors. The tensor interaction is shown to be important to explain the structureless nature of the angular distributions.