NSR Query Results
Output year order : Descending NSR database version of May 1, 2024. Search: Author = H.Helppi Found 34 matches. 1987HO15 Phys.Lett. 195B, 321 (1987) R.Holzmann, I.Ahmad, B.K.Dichter, H.Emling, R.V.F.Janssens, T.L.Khoo, W.C.Ma, M.W.Drigert, U.Garg, D.C.Radford, P.J.Daly, Z.Grabowski, H.Helppi, M.Quader, W.Trzaska Evolution of Nuclear Structure with Increasing Spin and Internal Excitation Energy in 152Dy NUCLEAR REACTIONS 76Ge(80Se, 4n), E=311 MeV; 120Sn(36S, 4n), E=157 MeV; measured Eγ, Iγ, total γ-spectrum. 152Dy deduced average γ-multiplicities, γ-multipolarity, spectral shapes, decay path to isomer.
doi: 10.1016/0370-2693(87)90025-6
1986GA21 Phys.Lett. 180B, 319 (1986) U.Garg, A.Chaudhury, M.W.Drigert, E.G.Funk, J.W.Mihelich, D.C.Radford, H.Helppi, R.Holzmann, R.V.F.Janssens, T.L.Khoo, A.M.van den Berg, J.L.Wood Lifetime Measurements in 184Pt and the Shape Coexistence Picture NUCLEAR REACTIONS 154Sm(34S, 4n), E=160 MeV; measured γ spectra, recoil distance. 184Pt deduced levels, T1/2, B(E2), shape coexistence. Recoil distance technique, enriched target.
doi: 10.1016/0370-2693(86)91195-0
1986MC14 Z.Phys. A325, 27 (1986) J.McNeill, R.Broda, Y.H.Chung, P.J.Daly, Z.W.Grabowski, H.Helppi, M.Kortelahti, R.V.F.Janssens, T.L.Khoo, R.D.Lawson, D.C.Radford, J.Blomqvist Level Structure of Proton-Rich N = 83 Nuclei 150Ho and 152Tm NUCLEAR REACTIONS 92Zr, 94Mo(60Ni, np), 93Nb(60Ni, n2p), E=240-250 MeV; measured γγ-coin, sum spectra, γ(t). 150Ho, 152Tm deduced levels, J, π, isomer, T1/2, decay characteristics, B(λ), γ-branching, γ-multipolarity, ICC. Enriched metallic targets, NaI sum spectrometer, Ge(Li) detectors. Shell model calculations.
1985BR07 Z.Phys. A321, 287 (1985) R.Broda, P.J.Daly, Z.W.Grabowski, H.Helppi, M.Kortelahti, J.McNeill, R.V.F.Janssens, R.D.Lawson, D.C.Radford, J.Blomqvist Two-Proton Neutron-Hole Yrast Excitations in 14766Dy81 NUCLEAR REACTIONS 89Y(60Ni, np), 90Zr(60Ni, n2p), 92Zr(58Ni, n2p), E=230-250 MeV; measured Eγ, Iγ, γγ-coin. 147Dy deduced levels, J, π, yrast sequence, γ-multipolarity, branching, transition widths, ICC, seniority characteristics, B(λ), configurations.
doi: 10.1007/BF01493450
1985RA22 Phys.Rev.Lett. 55, 1727 (1985) D.C.Radford, I.Ahmad, R.Holzmann, R.V.F.Janssens, T.L.Khoo, M.L.Drigert, U.Garg, H.Helppi Total γ-Ray Spectrum in 153Ho: From the yrast line into the continuum NUCLEAR REACTIONS 120Sn(37Cl, 4n), E=165 MeV; measured Eγ, Iγ. 153Ho deduced yrast, preyrast transitions, stretched transition multipole decomposition.
doi: 10.1103/PhysRevLett.55.1727
1984CH11 Phys.Rev. C29, 2153 (1984) Y.H.Chung, P.J.Daly, H.Helppi, R.Broda, Z.W.Grabowski, M.Kortelahti, J.McNeill, A.Pakkanen, P.Chowdhury, R.V.F.Janssens, T.L.Khoo, J.Blomqvist Four-Valence-Proton Yrast States in 15068Er82 NUCLEAR REACTIONS 92,94Zr, 93Nb, 92,94,95Mo(58Ni, xnyp), (60Ni, xnyp), 93Nb(60Ni, 2np), 95Mo(58Ni, n2p), E=225-255 MeV; measured Eγ, Iγ, γγ(t), σ(Eγ, E), γγ-coin, X-rayγ-coin. 150Er deduced levels, T1/2, yrast sequence, isomers, ICC, γ-branching, J, π, B(E2), γ-multipolarity. Shell model.
doi: 10.1103/PhysRevC.29.2153
1984LO12 ATOMKI Kozlem. 26, 29 (1984) T.Lonnroth, J.Hattula, H.Helppi, S.Juutinen, K.Honkanen, A.Kerek Study of Band Crossings in 130Xe NUCLEAR REACTIONS 130Te(α, 4n), E not given; measured γ-spectra. 130Xe deduced levels, J, π, band structure, γ-multipolarity. Triaxial cranking shell model. In-beam spectroscopy.
1984LO19 Nucl.Phys. A431, 256 (1984) T.Lonnroth, J.Hattula, H.Helppi, S.Juutinen, K.Honkanen, A.Kerek Study of Band Crossings in 130Xe NUCLEAR STRUCTURE 130Xe; calculated levels, band structure; deduced quasiparticle content. Cranked shell model. NUCLEAR REACTIONS 130Te(α, 4n), E=42-51 MeV; measured γγ-coin, Iγ(E), γ(θ). 130Xe deduced levels, J, π, band structure.
doi: 10.1016/0375-9474(84)90174-X
1983HA30 Phys.Rev. C28, 1860 (1983) J.Hattula, S.Juutinen, H.Helppi, A.Pakkanen, M.Piiparinen, S.Elfstrom, Th.Lindblad Band Crossings in 86Zr NUCLEAR REACTIONS Sr(3He, xnγ), E=27 MeV; Sr(α, xnγ), E=55 MeV; measured Eγ, Iγ, γγ(t), γ(θ). 86Zr deduced levels, T1/2, band structure, yrast line backbending characteristics.
doi: 10.1103/PhysRevC.28.1860
1983HE14 Phys.Rev. C28, 1382 (1983) H.Helppi, S.K.Saha, P.J.Daly, S.R.Faber, T.L.Khoo Rotation-Aligned Bands in 196Hg NUCLEAR REACTIONS 196Pt(α, 4n), E=48.6 MeV; measured Eγ, Iγ(θ), γγ(t), γγ-coin. 196Hg deduced high-spin levels, J, π, backbending, γ-branching. Cranked shell model.
doi: 10.1103/PhysRevC.28.1382
1983KH03 Phys.Scr. T5, 16 (1983) T.L.Khoo, P.Chowdhury, H.Emling, D.Frekers, R.V.F.Janssens, W.Kuhn, A.Pakkanen, Y.H.Chung, P.J.Daly, Z.W.Grabowski, H.Helppi, M.Kortelahti, S.Bjornholm, J.Borggreen, J.Pedersen, G.Sletten Nuclear Shape Transitions and Some Properties of Aligned-Particle Configurations at High Spin NUCLEAR STRUCTURE 148,152,156,160Dy, 147Gd; analyzed high-spin state, effective quadrupole moment, feeding times data; deduced shape dependence on spin, neutron number. NUCLEAR REACTIONS 122Sn(30Si, 5n), E not given; measured γγ-coin. 147Gd deduced levels, γ-branching.
doi: 10.1088/0031-8949/1983/T5/003
1983KO45 Phys.Lett. 131B, 305 (1983) M.Kortelahti, R.Broda, Y.H.Chung, P.J.Daly, H.Helppi, J.Mcneill, A.Pakkanen, P.Chowdhury, R.V.F.Janssens, T.L.Khoo, W.Kuhn Level Structure of 153Dy and the Competition between Collective and Few-Particle Excitation Modes in Dy Nuclei NUCLEAR REACTIONS 124Sn(34S, 5n), E=145-165 MeV; measured γ(θ), σ(Eγ, E), γγ-coin, γγ(t). 153Dy deduced levels, γ-branching, isomer configuration, J, π, B(E2), shape, collective, few particle excitation mode competitions.
doi: 10.1016/0370-2693(83)90504-X
1982HA44 Phys.Scr. 26, 205 (1982) In-Beam Study of 122,124,126Xe NUCLEAR REACTIONS 122,124,126Te(3He, 3n), E=20-27 MeV; measured Eγ, Iγ, I(ce), γ(θ), σ(Eγ) vs E, γγ-coin. 122,124,126Xe deduced levels, J, π, ICC, δ, γ-branching, band structure. 126Xe deduced isomer J, π, T1/2.
doi: 10.1088/0031-8949/26/3/011
1982HE08 Phys.Lett. 115B, 11 (1982) H.Helppi, Y.H.Chung, P.J.Daly, S.R.Faber, A.Pakkanen, I.Ahmad, P.Chowdhury, Z.W.Grabowski, T.L.Khoo, R.D.Lawson, J.Blomqvist Yrast (πh11/2)(n) Excitations in Proton-Rich N = 82 Nuclei NUCLEAR REACTIONS 92,94Zr, 93Nb, 92,94,95Mo(58Ni, X), (62Ni, X), E=225-285 MeV; measured σ(Eγ), γγ-, γ(X-ray)-coin. 150Er, 151Tm deduced levels, γ-branching, J, π, isomer T1/2, B(λ), configuration.
doi: 10.1016/0370-2693(82)90504-4
1982PA10 Phys.Rev.Lett. 48, 1530 (1982) A.Pakkanen, Y.H.Chung, P.J.Daly, S.R.Faber, H.Helppi, J.Wilson, P.Chowdhury, T.L.Khoo, I.Ahmad, J.Borggreen, Z.W.Grabowski, D.C.Radford Transition from Collective to Aligned-Particle Configurations at High Spin in 154Dy NUCLEAR REACTIONS 124Sn(34S, 4n), E=145-165 MeV; measured γγ-coin, γ(θ), σ(Eγ), recoil. 154Dy deduced levels, J, π, γ-branching, T1/2, yrast level intrinsic quadrupole moments, backbending, shape change.
doi: 10.1103/PhysRevLett.48.1530
1981DO05 J.Phys.(London) G7, 1379 (1981) F.Donau, J.Hattula, H.Helppi, A.Luukko, M.Jaaskelainen How to Describe Low-Lying Bands in Odd-A Transitional Xenon Nuclei NUCLEAR STRUCTURE 123,125,127,129Xe; calculated levels, band structure. Core-quasiparticle model.
doi: 10.1088/0305-4616/7/10/015
1981GO04 Nucl.Phys. A357, 109 (1981) L.Goettig, Ch.Droste, A.Dygo, T.Morek, J.Srebrny, R.Broda, J.Styczen, J.Hattula, H.Helppi, M.Jaaskelainen In-Beam Study of the 128,130Xe Nuclei NUCLEAR REACTIONS 126,128Te(α, 2nγ), E=25.5-27 MeV; 128,130Te(3He, 3nγ), E=20-27 MeV; measured Eγ, Iγ(θ), I(ce), γγ(t), αγ(t), 3Heγ(t), σ(Eγ). 128,130Xe deduced levels, J, π, T1/2, γ-multipolarity, δ, ICC.
doi: 10.1016/0375-9474(81)90628-X
1981HE04 Nucl.Phys. A357, 333 (1981) H.Helppi, J.Hattula, A.Luukko, M.Jaaskelainen, F.Donau In-Beam Study of 127,129Xe and Collective Description of the Level Structures in Odd-A Xe Nuclei NUCLEAR REACTIONS 126Te(3He, 2n), 128,130Te(3He, 4n), E=20-27 MeV; 126Te(α, n), E=18 MeV; measured Eγ, Iγ(θ), γγ-coin, γ(t), I(ce). 127,129Xe deduced levels, J, π, T1/2, ICC, δ(E2/M1). Enriched targets. NUCLEAR STRUCTURE 123,125,127,129Xe; calculated levels, band structure. Triaxial rotor, core plus quasiparticle model calculations.
doi: 10.1016/0375-9474(81)90225-6
1981HE07 Phys.Rev. C23, 1446 (1981) H.Helppi, S.K.Saha, P.J.Daly, S.R.Faber, T.L.Khoo, F.M.Bernthal High-Spin Level Spectra of the Nuclei 195Pb, 197Pb, 199Pb, and 201Pb NUCLEAR REACTIONS 200,198Hg(α, 3n), E=35-45 MeV; 198Hg(3He, 4n), E=38 MeV; 198Hg(3He, 6n), 199Hg(3He, 7n), E=74 MeV; measured Eγ, Iγ(θ), γγ-coin, γγ(t). 195,197,199,201Pb deduced high-spin levels, J, π, T1/2.
doi: 10.1103/PhysRevC.23.1446
1981HE10 Phys.Rev. C23, 2345 (1981) H.Helppi, S.K.Saha, M.Piiparinen, C.L.Dors, P.J.Daly, T.L.Khoo High-Spin Level Structure of 200Hg NUCLEAR REACTIONS 198Pt(α, 2n), E=26-28 MeV; measured Eγ, Iγ(θ), γγ-coin. 200Hg deduced high-spin levels, J, π, γ-multipolarity.
doi: 10.1103/PhysRevC.23.2345
1981LU01 Nucl.Phys. A357, 319 (1981) A.Luukko, J.Hattula, H.Helppi, O.Knuuttila, F.Donau Level Structure in 123Xe NUCLEAR REACTIONS 122Te(3He, 2n), 123Te(3He, 3n), E=14-27 MeV; measured Eγ, Iγ(θ), γγ-coin, γ(t), I(ce). 123Xe deduced levels, J, π, T1/2, ICC, δ(E2/M1). Enriched targets.
doi: 10.1016/0375-9474(81)90224-4
1979HE15 Nucl.Phys. A332, 183 (1979) Even- and Odd-Parity Band Structures in 125Xe NUCLEAR REACTIONS 125Te(3He, 3nγ), E=20-27 MeV; measured Eγ, Iγ(θ), γγ-coin, γ(t). 125Xe deduced levels, J, π, T1/2. Enriched target.
doi: 10.1016/0375-9474(79)90103-9
1977HE06 Phys.Lett. 67B, 279 (1977) H.Helppi, S.K.Saha, P.J.Daly, S.R.Faber, T.L.Khoo, F.M.Bernthal High-Spin Neutron Hole Excitations in Light Odd-A Pb Nuclei NUCLEAR REACTIONS 198,200,202Hg(α, 3nγ), (3He, xnγ), E=not given; measured σ(E), Eγ, Iγ, γγ(t). 195,197,199,201,203Pb deduced levels, T1/2, J, π.
doi: 10.1016/0370-2693(77)90370-7
1977SA18 Phys.Rev. C16, 2159 (1977) S.K.Saha, H.Helppi, P.J.Daly, S.R.Faber, T.L.Khoo, F.M.Bernthal High-Spin Level Structure of the Five Neutron Hole Nucleus 203Pb NUCLEAR REACTIONS 202Hg(α, 3nγ), E=38.2 MeV; measured Eγ, Iγ, γγ-coin, γ(θ, t). 203Pb deduced levels, J, π, T1/2.
doi: 10.1103/PhysRevC.16.2159
1975HE13 Nucl.Phys. A247, 317 (1975) H.Helppi, A.Pakkanen, J.Hattula Mixing of the Transitions from the 3+ Quasi γ-Band Level in 152Gd RADIOACTIVITY 152Eu [from 151Eu(n, γ)]; measured γγ(θ). 152Gd deduced B(E2) ratios, γ-multipole mixing. Enriched target.
doi: 10.1016/0375-9474(75)90638-7
1975PA07 Z.Phys. A274, 127 (1975) A.Pakkanen, M.Kortelahti, H.Helppi, J.Kantele, T.Poikolainen, R.Komu Decay of 14.6 h 90Nb RADIOACTIVITY 90Nb [from 90Zr(p, n)]; measured Eγ, Iγ, γγ-coin; deduced log ft. 90Zr deduced levels, J, π, γ-branching. Ge(Li), anti-Compton detectors. Natural targets.
doi: 10.1007/BF01408464
1974HE08 Nucl.Phys. A223, 13 (1974) H.Helppi, A.Pakkanen, J.Hattula The E2/M1 Mixing of the Transitions from the Kπ = 2+ Bands in 190,192Os and 192Pt RADIOACTIVITY 190Ir [from 192Os(p, 3n)], 192Ir [from 191Ir(n, γ)]; measured γγ, γγ(θ). 190,192Os, 192Pt deduced γ-multipole mixing. Natural targets.
doi: 10.1016/0375-9474(74)90276-0
1973PA08 Nucl.Phys. A206, 164 (1973) A.Pakkanen, P.Puumalainen, H.Helppi, T.Komppa Isomeric Transition in 198Au RADIOACTIVITY 198mAu [from 197Au(d, p), 198Hg(n, p)]; measured T1/2, Eγ, ICC, Iγ, I(ce), γγ-, ceγ-coin, γγ-delay, ICC; 198Au deduced levels, J, π, T1/2.
doi: 10.1016/0375-9474(73)90613-1
1972HE36 Z.Phys. 255, 385 (1972) Note on the Decay of 200Au RADIOACTIVITY 200Au; measured Eγ, Iγ, Eβ, βγ-, γγ-coin; deduced log ft, Q. 200Hg deduced levels, J, π, γ-branching. Ge(Li), plastic detectors.
doi: 10.1007/BF01392472
1972PA06 Nucl.Phys. A184, 157 (1972) A.Pakkanen, T.Komppa, H.Helppi New 204Au Activity and the Decay of 202Au RADIOACTIVITY 202Au[from 202Hg(n, p), 205Tl(n, α)], 204Au[from 204Hg(n, p)]; measured T1/2, Eγ, Iγ, γγ, γβ-coin; deduced log ft. 202,204Hg deduced levels, J, π, γ-branching. Natural targets.
doi: 10.1016/0375-9474(72)90450-2
1972PA24 Z.Phys. 254, 98 (1972) A.Pakkanen, H.Helppi, T.Komppa, P.Puumalainen Low-Lying Levels of 201Hg from the Decay of 201Au RADIOACTIVITY 201Au; measured Eγ, Iγ, γγ-coin, Eβ, βγ-coin, Xγ-coin; deduced Q, log ft. 201Hg deduced levels, J, π, γ-branching. Ge(Li), Si(Li), NaI(Tl) detectors.
doi: 10.1007/BF01380058
1972PA38 Comment.Phys.-Math. 42, 267 (1972) A.Pakkanen, T.Komppa, H.Helppi On Low-Lying Levels in Stable Even Mercury Isotopes RADIOACTIVITY 202,204Au; measured T1/2. 202,204Hg deduced levels.
1971HA09 Z.Phys. 241, 117 (1971) J.Hattula, H.Helppi, J.Kantele Directional Correlations of Some γ-Ray Cascades in 200Hg RADIOACTIVITY 200Tl; measured γγ(θ). 200Hg levels deduced γ-mixing, J, π.
doi: 10.1007/BF01397900
1970HE29 Phys.Scr. 2, 155 (1970) Multipole Character of Some Gamma Transitions in 152Sm RADIOACTIVITY 152Eu; measured γγ(θ). 152Sm levels deduced J, π, γ-mixing. Ge(Li), NaI(Tl) detectors.
doi: 10.1088/0031-8949/2/4-5/005
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