Heavy-Ion Beam Acceleration of Two-Charge States from an Ecr Ion Source

This paper describes a design for the front end of a superconducting (SC) ion linac which can accept and simultaneously accelerate two charge states of uranium from an ECR ion source. This mode of operation increases the beam current available for the heaviest ions by a factor of two. We discuss the 12 MeV/u prestripper section of the Rare Isotope Accelerator (RIA) driver linac including the LEBT, RFQ, MEBT and SC sections, with a total voltage of 112 MV. The LEBT consists of two bunchers and electrostatic quadrupoles. The fundamental frequency of both bunchers is half of the RFQ frequency. The first buncher is a multiharmonic buncher, designed to accept more than 80% of each charge state and to form bunches of extremely low longitudinal emittance (rms emittance is lower than 0.2 keV/u nsec) at the output of the RFQ. The second buncher is located directly in front of the RFQ and matches the velocity of each charge-state bunch to the design input velocity of the RFQ. We present full 3D simulations of a two-charge-state uranium beam including space charge forces in the LEBT and RFQ, realistic distributions of all electric and magnetic fields along the whole prestripper linac, and the effects of errors, evaluated for several design options for the prestripper linac. The results indicate that it is possible to accelerate two charge states while keeping emittance growth within tolerable limits.Comment: LINAC2000, MOD0

Isotope thermometery in nuclear multifragmentation

A systematic study of the effect of fragment$-$fragment interaction, quantum statistics, $\gamma$-feeding and collective flow is made in the extraction of the nuclear temperature from the double ratio of the isotopic yields in the statistical model of one-step (Prompt) multifragmentation. Temperature is also extracted from the isotope yield ratios generated in the sequential binary-decay model. Comparison of the thermodynamic temperature with the extracted temperatures for different isotope ratios show some anomaly in both models which is discussed in the context of experimentally measured caloric curves.Comment: uuencoded gzipped file containing 20 pages of text in REVTEX format and 12 figures (Postscript files). Physical Review C (in press

HPV-negative cervical cancer: a distinct type of the uterine cervix with poor prognosis

The real-time PCR method was used to study cervical scrapings from 116 patients with stag

Disease-free and overall survival of patients diagnosed with HPV-associated or HPV-negative cervical cancer

The real-time PCR method is used to study scrapings of cervical epithelium and outer portion of the cervix in 116 patients aged 24–79 years with stage I–IV primary cervical cancer. The comprehensive survey included colposcopy, cytological and histological analysis, detection and genotyping of high-risk human papillomavirus. In 84 patients (72.4%) the presence of human papillomavirus (HPV) of high carcinogenic risk (HCR) is found, in 32 patients (27.6%) the presence of the virus has not been inspected in the tumor. A significant decrease in the survival rate as well as the prevalence of the worst prognosis for patients with HPV-negative cervical cancer are shown

НеоадЪювантная химиотерапия при лечении местнораспространенного рака шейки матки

Different modes of treatment of 78 patients with stage IIb-IIIb locally advanced cervical cancer were assessed. The study group comprised 30 patients who received 2 courses of neoadjuvant chemotherapy followed by combined curative radiation therapy. The comparison group included 20 patients who received combined radiation therapy with cisplatin radiomodification. The control group consisted of 28 patients who received combined curative radiation therapy. Neoadjuvant chemotherapy was found to promote more rapid symptom relief, significant reduction in primary tumor volume and improvement of tumor resectability. The assessment of long-term outcomes showed a significantincrease in recurrence-free and overall survival rates in patients treated with neoadjuvant chemotherapy compared to patients treated with radiation therapy without adjuvant chemotherapy. Neoadjuvant chemotherapy resulted in more pronounced positive changes in values of functional scale as well as in significant improvement of general health status of patients compared to other group patientsПроведена оценка различных методов лечения 78 больных местнораспространенным раком шейки матки (МРРШМ) IIb-IIIb стадий. Основную группу составили 30 больных, получивших 2 курса неоадьювантной химиотерапии с последующей сочетаннойлучевой терапией по радикальной программе. В группу сравнения вошли 20 пациенток, получившие сочетанную лучевую терапию с радиомодификацией цисплатином. Группу контроля составили 28 пациенток, перенесших сочетанную лучевую терапию по радикальной программе. Установлено, что НАХТ способствует более быстрому купированию клинических симптомов заболевания, значимому уменьшению объема первичной опухоли и повышению ее резектабельности. Оценка отдаленных результатов исследования показала значимое увеличение безрецидивной и общей выживаемости в группе больных с НАХТ по сравнению с группой больных, получивших лучевое лечение. Проведение НАХТ способствует более выраженной положительной динамике показателей функциональных шкал, а также значимому увеличению общего статуса здоровья по сравнению с другими группами

Isoscalar Giant Dipole Resonance and Nuclear Matter Incompressibility Coefficient

We present results of microscopic calculations of the strength function, S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar giant dipole resonance (ISGDR). An accurate and a general method to eliminate the contributions of spurious state mixing is presented and used in the calculations. Our results provide a resolution to the long standing problem that the nuclear matter incompressibility coefficient, K, deduced from sigma(E) data for the ISGDR is significantly smaller than that deduced from data for the isoscalar giant monopole resonance (ISGMR).Comment: 4 pages using revtex 3.0, 3 postscript figures created by Mathematica 4.

Hydrogen absorption and 57 Fe Mössbauer effect in UFeGe

Abstract. Hydrogenation of UFeGe transforms the monoclinic type of structure into the orthorhombic (TiNiSi-type) and subsequently to the hexagonal (ZrBeSi-type) structure. It does not induce magnetic order, however magnetic susceptibility is enhanced. The Sommerfeld coefficient γ increases from 12 mJ/mol K 2 in UFeGe to 36 mJ/mol K 2 in UFeGeH 1.7-1.8 (β-hydride). The observed variations of electronic properties are mainly due to the modified geometry of the lattice, characterized by enhanced inter-uranium spacing, and reduced 5f-3d hybridization in the hydrides

Memory effects on descent from nuclear fission barrier

Non-Markovian transport equations for nuclear large amplitude motion are derived from the collisional kinetic equation. The memory effects are caused by the Fermi surface distortions and depend on the relaxation time. It is shown that the nuclear collective motion and the nuclear fission are influenced strongly by the memory effects at the relaxation time $\tau \geq 5\cdot 10^{-23}{\rm s}$. In particular, the descent of the nucleus from the fission barrier is accompanied by characteristic shape oscillations. The eigenfrequency and the damping of the shape oscillations depend on the contribution of the memory integral in the equations of motion. The shape oscillations disappear at the short relaxation time regime at $\tau \to 0$, which corresponds to the usual Markovian motion in the presence of friction forces. We show that the elastic forces produced by the memory integral lead to a significant delay for the descent of the nucleus from the barrier. Numerical calculations for the nucleus $^{236}$U shows that due to the memory effect the saddle-to-scission time grows by a factor of about 3 with respect to the corresponding saddle-to-scission time obtained in liquid drop model calculations with friction forces.Comment: 22 pages, 8 figures, submitted to Phys. Rev.