We have studied the fission-neutron emission competition in highly excited 274 Hs (Z=108) (where the fission barrier is due to shell effects) formed by a hot fusion reaction. Matching cross bombardments ( 26 Mg + 248 Cm and 25 Mg + 248 Cm) were used to identify the properties of first chance fission of 274 Hs. A Harding-Farley analysis of the fission neutrons emitted in the 25,26 Mg + 248 Cm was performed to identify the pre-and post-scission components of the neutron multiplicities in each system. (Γn/Γt) for the first chance fission of 274 Hs (E * = 63 MeV) is 0.89 ± 0.13, i.e., ∼ 90 % of the highly excited nuclei survive.The high value of that survival probability is due to dissipative effects during de-excitation. A proper description of the survival probabilities of excited superheavy nuclei formed in hot fusion reactions requires consideration of both dynamic and static (shell-related) effects.The remarkable recent progress in the synthesis of new heavy and superheavy nuclei has been made using fusion reactions. These reactions can be divided into two prototypical classes, "cold" and "hot" fusion reactions. In "cold" fusion reactions, one bombards Pb or Bi target nuclei with heavier projectiles (Ca-Kr) to form completely fused systems with low excitation energies (E * =10-15 MeV), leading to a higher survival (against fission) but with a reduced probability of the fusion reaction taking place due to the larger Coulomb repulsion in the more symmetric reacting system. (This approach has been used in the synthesis of elements 107-113). In "hot" fusion reactions one uses a more asymmetric reaction (typically involving a lighter projectile and an actinide target nucleus) to increase the fusion probability but leading to a highly excited completely fused system (E * =30-60 MeV) with a reduced probability of surviving against fission. (This approach has been used to synthesize elements 102-118.) Formally, the cross section for producing a heavy evaporation residue, σ EVR , in a fusion reaction can be written as(1) where σ capture (E c.m. , J) is the capture cross section at center of mass energy E c.m. and spin J. P CN is the probability that the projectile-target system will evolve from the contact configuration inside the fission saddle point to form a completely fused system rather than re-separating (quasifission, fast fission). W sur is the probability that the completely fused system will de-excite by neutron emission rather than fission. For a quantitative understanding of the synthesis of new heavy nuclei, one needs to understand σ capture , P CN , and W sur for the reaction system under study.Formally W sur can be written as

Background:11 Li is one of the most studied halo nuclei. The fusion of 11 Li with 208 Pb has been the subject of a number of theoretical studies with widely differing predictions, ranging over four orders of magnitude, for the fusion excitation function.Purpose: To measure the excitation function for the 11 Li + 208 Pb reaction. Methods: A stacked foil/degrader assembly of 208 Pb targets was irradiated with a 11 Li beam producing center of target beam energies from above barrier to near barrier energies ( 40 to 29 MeV). The intensity of the 11 Li beam (chopped) was 1250 p/s and the beam on-target time was 34 hours. The α-decay of the stopped EVRs was detected in an α-detector array at each beam energy in the beam-off period (the beam was on for ≤ 5 ns and then off for 170 ns).Results: The observed nuclidic yields of 212/215 At and 214 At are consistent with being produced in the complete fusion of 11 Li with 208 Pb. The observed yields of 213 At appear to be the result of the breakup of 11 Li into 9 Li + 2n, with the 9 Li fusing with 208 Pb. The magnitudes of the total fusion cross sections are substantially less than most theoretical predictions.Conclusions: It is possible to measure the evaporation residue production cross-sections resulting from the interaction of 11 Li with 208 Pb using current generation radioactive beam facilities. Both complete fusion and breakup fusion processes occur in the interaction of 11 Li with 208 Pb. An important breakup process leads to the fusion of the 9 Li fragment with 208 Pb .

Abstract. Formally, the cross section for producing a heavy evaporation residue, σ EVR , in a fusion reaction can be written aswhere E is the center of mass energy, and T is the probability of the colliding nuclei to overcome the potential barrier in the entrance channel and reach the contact point. P CN is the probability that the projectile-target system will evolve from the contact point to the compound nucleus. W sur is the probability that the compound nucleus will decay to produce an evaporation residue rather than fissioning. However, one must remember that the W sur term effectively sets the allowed values of the spin, which in turn, restricts the values of the capture and fusion cross sections. We point out the implications of this fact for capture cross sections for heavy element formation reactions.

A 41 year-old man was referred to the National Institutes of Health (NIH) for evaluation of extensive skin thickening and rippled appearance of his upper extremities, torso, and lower extremities. The patient was day +671 status post a myeloablative 6/6 HLA-matched related (sister) peripheral blood stem cell transplant for acute myelogenous leukemia. The conditioning regimen consisted of busulfan and cyclophosphamide and graft-versus-host disease prophylaxis included tacrolimus and a short course of methotrexate.The patient's cutaneous symptoms began approximately eight months post-transplant with the onset of "red dots" on his skin accompanied by decreased range of motion at the wrists. A biopsy a patch on the right forearm demonstrated non-specific histologic findings of a mild superficial perivascular infiltrate with rare neutrophils. Prior to the NIH consultation, the patient had been treated with oral steroids, hydroxychloroquine sulfate, rituximab, thalidomide, and physical therapy without benefit. He had not been treated with phototherapy. Rather, the patient reported that the skin changes and range of motion at several joints continued to worsen, resulting in significant functional limitations. His immunosuppression regimen at the time of referral consisted of methylprednisolone 32 mg daily, tacrolimus 1.5 mg twice daily, hydroxychloroquine 200 mg twice daily, mycophenolate mofetil 1 g twice daily, and thalidomide 200 mg in the evening. Physical ExaminationPhysical exam was remarkable for a widespread puckered, cellulite-like appearance of the bilateral inner upper arm, majority of the anterior torso, bilateral flanks, medial buttocks, and

Formally, the cross section for producing a heavy evaporation residue, σ EVR , in a complete fusion reaction is given as σ EVR (E) = πh 2 2µE ∞ =0 (2 + 1)T (E,)P CN (E,)W sur (E,) (1) where E is the center of mass energy. P CN is the fusion probability and W sur is the probability that the compound nucleus will decay by emitting particles rather than fissioning. The first term represents the capture cross section. Notice that all terms depend on and the cross section depends on the product of these terms, which are not separable. When W sur is zero or a small number due to low fission barriers at high angular momenta, the capture and fusion terms will be limited. For a series of ∼ 287 reactions leading to heavy evaporation residues with Z CN ≤ 110, we point out the implications of this fact for capture cross sections for heavy element formation reactions. From a comparison of calculated and measured evaporation residue cross sections we deduce values of the fusion probability, P CN , for some of these reactions.