Novel Internal Target for Electron Scattering off Unstable Nuclei

A novel internal target has been developed, which will make electron scattering off short-lived radioactive nuclei possible in an electron storage ring. An "ion trapping" phenomenon in the electron storage ring was successfully utilized for the first time to form the target for electron scattering. Approximately 7E6 stable 133Cs ions were trapped along the electron beam axis for 85 ms at an electron beam current of 80 mA. The collision luminosity between the stored electrons and trapped Cs ions was determined to be 2:4(8)E25 cm-2s-1 by measuring elastically scattered electrons

First Demonstration of Electron Scattering Using a Novel Target Developed for Short-Lived Nuclei

We carried out a demonstrative electron scattering experiment using a novel ion-trap target exclusively developed for short-lived highly unstable nuclei. Using stable 133Cs ion as a target, this experiment completely mimicked electron scattering off short-lived nuclei. Achieving a luminosity higher than1E26 cm-2 s-1 with around only 1E6 trapped ions on the electron beam, the angular distribution of elastic scattering was successfully measured. This experiment clearly demonstrates that electron scattering off rarely produced short-lived nuclei is practical with this target technique

Progress in the R&D Experiments About a Novel Method of Electron Scattering off Short-lived Nuclei

A novel method has been established to realize the experiment of electron scattering off short-lived nuclei. The method was based on the well known "ion trapping" phenomenon in electron storage rings. In the R&D experiments at Kyoto University, stable nucleus, 133Cs, was employed as the target nucleus. The luminosity of scattering experiment was nearly 1026 cm−2s−1 at electron beam current around 75 mA. The angular distribution of elastically scattered electrons from trapped Cs ions was measured and the result was well fitted by theoretical calculation. It was indicated that higher luminosity can be reached with larger electron beam current

Signet ring cell carcinoma of the ampulla of vater: Report of a case and a review of the literature

Introduction: Signet ring cell carcinoma (SRCC) of the ampulla of vater is a very rare tumor that is reported infrequently in the literature. Presentation of case: A 59-year-old woman visited our hospital for evaluation of elevated transaminase levels. On laboratory examination of tumor marker levels, carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19–9 levels were normal, and DUPAN-2 was elevated. Computed tomography (CT) confirmed a 2 cm, enhanced mass in the periampullary region, with marked common bile duct dilatation. Endoscopic retrograde cholangiopancreatography (ERCP) showed a swollen papilla of vater, with a reddish, erosive mucosa. Histological examination of biopsy samples from the ampulla of vater showed signet ring cell carcinoma (SRCC). The patient underwent radical pancreatoduodenectomy. Pathological examination showed that the SRCC had infiltrated into the duodenal muscularis propria and pancreatic parenchyma, and lymph node metastases were identified around the abdominal aorta and common hepatic artery. Based on the immunohistochemical staining patterns of the positive results for CDX2 and MUC2, the tumor cells in the present case appeared to have an intestinal type origin. The ampullary cancer was diagnosed as T3bN1M1, Stage IV according to the International Union Against Cancer TNM classification (UICC). After undergoing adjuvant chemotherapy with cisplatin–gemcitabine chemotherapy for 6 months, the patient has remained disease-free in the 7 months since surgery. Discussion: SRCC of intestinal-type origin is associated with a favorable outcome. Conclusion: Investigation to confirm the histological origin of SRCC by immunohistochemical staining might inform the treatment strategy and identify patients with ampullary SRCC who may have a good prognosis

Development and operation of an electrostatic time-of-flight detector for the Rare RI storage Ring

An electrostatic time-of-flight detector named E-MCP has been developed for quick diagnostics of circulating beam and timing measurement in mass spectrometry at the Rare-RI Ring in RIKEN. The E-MCP detector consists of a conversion foil, potential grids, and a microchannel plate. Secondary electrons are released from the surface of the foil when a heavy ion hits it. The electrons are accelerated and deflected by 90◦toward the microchannel plate by electrostatic potentials. A thin carbon foil and a thin aluminum-coated mylar foil were used as conversion foils. We obtained time resolutions of 69(1) ps and 43(1) ps (standard deviation) for a84Krbeam at an energy of 170 MeV/u when using the carbon and the aluminum-coated mylar foils, respectively. A detection efficiency of approximately 90% was obtained for both foils. The E-MCP detector equipped with the carbon foil was installed inside the Rare-RI Ring to confirm particle circulation within a demonstration experiment on mass measurements of nuclei around 78Ge produced by in-flight fission of uranium beam at the RI Beam Factory in RIKEN. Periodic time signals from circulating ions were clearly observed. Revolution times for 78Ge, 77Ga, and 76Zn were obtained. The results confirmed successful circulation of the short-lived nuclei inside the Rare-RI Ring