Isochronous Mass Measurements of Hot Exotic Nuclei

A novel method for mass measurements of short-lived exotic nuclides is presented. Exotic nuclides were produced and separated in flight at relativistic energies with the fragment separator (FRS) and were injected into the experimental storage ring (ESR). Operating the ESR in the isochronous mode we performed mass measurements of neutron deficient fragments of ⁸⁴Kr with half-lives larger than 50 ms. However, this experimental technique is applicable in a half-life range down to a few μs. A mass resolving power of 110000 (FWHM) has been achieved. Results are presented for the masses of ⁶⁸As, ^70,71Se and ⁷³Br. This revised version was published online in July 2006 with corrections to the Cover Date.     

Novel distance dependence of diffusion constants in hyaluronan aqueous solution resulting from its characteristic nano-microstructure.

Material transports in hyaluronan (HA) aqueous solution were investigated applying two different techniques, i.e., pulsed field gradient NMR (PFG-NMR) and photochemical quenching, to the measurement of diffusion constants to show a sharp contrast resulting from the difference of the spectroscopic observation time while the same probe molecules were commonly used in two experiments. The value from PFG-NMR reflects the relatively long transport along which the majority of the molecules are retarded by the mesh structure of HA solution. In such inhomogeneous fluids, the observable diffusion constant should generally depend on the observation time and, i.e., the averaged distance of diffusion. Quantitative discussion, which compares the obtained characteristic distance of diffusion with the pore size, clarifies the role of the nano-microstructure of HA solution forming small pores surrounded by the polymer chain networks.     

Status of the SHIPTRAP Project: A Capture and Storage Facility for Heavy Radionuclides fromSHIP

The ion trap facility SHIPTRAP is being set up to deliver very clean and cool beams of singly-charged recoil ions produced at the SHIP velocity filter at GSI Darmstadt. SHIPTRAP consists of a gas cell for stopping and thermalizing high-energy recoil ions from SHIP, an rf ion guide for extraction of the ions from the gas cell, a linear rf trap for accumulation and bunching of the ions, and a Penning trap for isobaric purification. The progress in testing the rf ion guide is reported. A transmission of about 93(5)% was achieved. This revised version was published online in July 2006 with corrections to the Cover Date.     

Charged particle spectra in αα and αp collisions at the CERN ISR

Momenta of charged particles produced in inelastic αα, αp, andpp collisions were measured using the Split-Field-Magnet detector at the CERN Intersecting Storage Rings. Inclusive and semi-in-clusive spectra are presented as a function of rapidityy, Feynman-x, and transverse momentump _T . The inclusivey distributions agree well with predictions of the dual parton model; the highest particle densities are reached aty?0 and the momenta of leading protons decrease significantly for increasing total multiplicity. ‘Temperatures’ are equal in αα, αp, andpp interactions. Thep _T distributions depend weakly on the multiplicity.     

Nuclear stopping power in αα anddd collisions

Inelasticαα anddd collisions were studied at a centre-of-mass energy √S _NN=31.2 GeV per nucleon-nucleon collision, using the Split-Field Magnet (SFM) detector at the CERN ISR. In this paper we show the inclusive and semi-inclusive rapidity distributions of protons, compare them with predictions of the Lund model, and calculate the average rapidity loss for participant protons. From the negative particles we calculate the inelasticity of the interaction, the average energy per particle, and the degree of isotropy of the produced hadrons.     

High spin structure in127Xe and125Xe

Excited states of the nuclei¹²⁷Xe and¹²⁵Xe have been investigated in the inverse kinematic reactions⁴⁸ Ca(⁸² Se,(3.5)n) at 275 MeV beam energy with the OSIRIS multidetector system at the VICKSI-accelerator of the HMI Berlin. The level scheme of¹²⁷Xe was extended up to a level of tentative spin (51/2^?). Two excited bands of 3QP-character were observed. For¹²⁵Xe these structures were extended towards higher spins. Experimental Routhians of selected bands are presented.     

The four-jet structure of large transverse momentum events inpp interactions at the ISR

Deep inelastic proton-proton collisions have been recorded with the Split-Field-Magnet Detector (SFM) at the CERN Intersecting Storage Rings (ISR) by triggering on a single particle at high transverse momentum. Full reconstruction of the charged particles in these collisions was performed. In this paper we demonstrate the existence of a structure comprised of four jet-like clusters, two longitudinal and two transverse with respect to the beam, as would be expected from hard scattering of proton constituents.