For the first time, the FRagment Separator (FRS) and the Multiple-Reflection Time-Of-Flight Mass-Spectrometer (MR-TOF-MS) particle identification (PID) systems at GSI have been coupled. This new ...approach adds to the standard FRS PID an additional unambiguous identification of the fragments and the possibility to identify and count long-lived isomeric states (>ms). For this purpose, single-event timestamp information given by a common clock was used to correlate both systems. Two methods were implemented to improve the signal-to-background ratio by more than a factor 2 in the high resolution mass spectrum obtained with the MR-TOF-MS for the 109In isotope. Moreover, the coupling of the systems allows an improvement in the on-line monitoring of the FRS-Ion Catcher (IC) efficiency and extraction time. In addition, range calculations were implemented in the on-line monitoring; a powerful tool for real-time optimization of stopped beam experiments.
PURPOSE: The purpose of this study was to evaluate the quality of the medical evidence available to the clinician in the practice of hematology/oncology.
METHODS: We selected 14 neoplastic ...hematologic disorders and identified 154 clinically important patient management decision/interventions, ranging from initial treatment decisions to those made for the treatment of recurrent or refractory disease. We also performed a search of the scientific literature for the years 1966 through 1996 to identify all randomized controlled trials in hematology/oncology.
RESULTS: We identified 783 randomized controlled trials (level 1 evidence) pertaining to 37 (24%) of the decision/interventions. An additional 32 (21%) of the decision/interventions were supported by evidence from single arm prospective studies (level 2 evidence). However, only retrospective or anecdotal evidence (level 3 evidence) was available to support 55% of the identified decision/interventions. In a retrospective review of the decision/interventions made in the management of 255 consecutive patients, 78% of the initial decision/interventions in the management of newly diagnosed hematologic/oncologic disorders could have been based on level 1 evidence. However, more than half (52%) of all the decision/interventions made in the management of these 255 patients were supported only by level 2 or 3 evidence.
CONCLUSIONS: We conclude that level 1 evidence to support the development of practice guidelines is available primarily for initial decision/interventions of newly diagnosed diseases. Level 1 evidence to develop guidelines for the management of relapsed or refractory malignant diseases is currently lacking.
We have developed a compact detector for measuring beam particles using plastic scintillators readout through Multi-Pixel Photon Counters, which is employed for hypernuclear measurements in the ...WASA-FRS experiment at GSI. The Time-of-Flight resolution of the newly-developed detector has been investigated in relation to the overvoltage with respect to the breakdown voltage, a maximum counting rate of approximately 3×106/s per segment, and a maximum beam charge of Z = 6. The evaluated Time-of-Flight resolutions between the neighboring segments of the detector range from 44.6±1.3 ps to 100.3±3.6 ps (σ) depending on the segment, overvoltage values, and beam intensity. It is also observed that the Time-of-Flight resolution is inversely correlated to the beam atomic charge (Z).
We report precision mass measurements of neutron-deficient gallium isotopes approaching the proton drip line. The measurements of 60–63Ga performed with the TITAN multiple-reflection time-of-flight ...mass spectrometer provide a more than threefold improvement over the current literature mass uncertainty of 61Ga and mark the first direct mass measurement of 60Ga. The improved precision of the 61Ga mass has important implications for the astrophysical rp process, as it constrains essential reaction Q values near the 60Zn waiting point. Based on calculations with a one-zone model, we demonstrate the impact of the improved mass data on prediction uncertainties of x-ray burst models. The first-time measurement of the 60Ga ground-state mass establishes the proton-bound nature of this nuclide, thus constraining the location of the proton drip line along this isotopic chain. Including the measured mass of 60Ga further enables us to extend the evaluated T = 1 isobaric multiplet mass equation up to A = 60.
Obesity in children is a rapidly growing problem and may be underrecognized by pediatricians. We reviewed 473 consecutive well child visits to assess frequency of correctly identifying overweight ...children. Of children with a body mass index greater than the 95th percentile for gender and age, only 27 (29%) were diagnosed as overweight by the physician. Our results suggest that the frequency of diagnosing children as overweight at well child visits is critically low.
At the FRS Ion Catcher (FRS-IC), projectile and fission fragments are produced at relativistic energies, separated in-flight, energy-bunched, slowed down, and thermalized in the ultra-pure helium ...gas-filled cryogenic stopping cell (CSC). Thermalized nuclei are extracted from the CSC using a combination of DC and RF electric fields and gas flow. This CSC also serves as the prototype for the CSC of the Super-FRS, where exotic nuclei will be produced at unprecedented rates making it possible to go towards the extremes of the nuclear chart. Therefore, it is essential to efficiently extract thermalized exotic nuclei from the CSC under high beam rate conditions, in order to use the rare exotic nuclei, which come as cocktail beams. The dependence of the extraction efficiency on the intensity of the impinging beam into the CSC was studied with a primary beam of 238U and its fragments. Tests were done with two different versions of the DC electrode structure inside the cryogenic chamber, the standard 1 m long and a short 0.5 m long DC electrode systems. In contrast to the rate capability of 104 ions/s with the long DC electrode system, results show no extraction efficiency loss up to the rate of 2 × 105 ions/s with the new short DC electrode. This order of magnitude increase of the rate capability paves the way for new experiments at the FRS-IC, including studies of exotic nuclei with in-cell multi-nucleon transfer reactions. The results further validate the design concept of the CSC of the Super-FRS, which was developed to effectively manage beams of even higher intensities.
The WASA-FRS project at GSI and its perspective Saito, T.R.; Achenbach, P.; Alfaki, H. Alibrahim ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
09/2023, Letnik:
542
Journal Article
Recenzirano
Odprti dostop
A novel technique to study bound states of exotic hadrons in subatomic nuclei, such as hypernuclei and mesic nuclei, has been developed by employing the Fragment Separator FRS and the WASA central ...detector at GSI. Two experiments, S447 for studying light hypernuclei, especially hypertriton and a Λnn bound state, and S490 for searching for η’ mesic-nuclei, were recently performed. Data analyses are currently in progress, and light charged particles such as protons and π± are clearly observed and identified in the both experiments. For S447, light nuclear fragments that can also be residual nuclei from decays of hypernuclei of interests have been analysed by the FRS, and a momentum resolution, Δp/p, of 5×10−4 has been achieved. Further data analyses are to be completed. The WASA-FRS project will be continued and extended with the FRS at FAIR Phase 0, and upgrading of the WASA magnet and detectors is currently in progress. Furthermore, construction of a larger detector system with the Super-FRS at FAIR Phase 1 is also under consideration.
The results of a clinically performed preoperative stair climb was compared to the presence of postthoracotomy complications
in the retrospective hospital record review of 54 adult men. The stair ...climb was a maximum of five flights (125 steps) performed
at the patient's rate and terminated at his request. Pulmonary function measurements and facets of the stair climb physiology
were also examined in reference to the presence, type, and severity of complications experienced. Most minor complications
such as transient arrhythmias, atelectasis, and pneumonia were clearly not predicted by the stair climb performance. The ability
to climb three flights preoperatively most clearly separated those patients having the longer postoperative intubation and
hospital stay, greater frequency of complications, and cumulative complication score (p less than 0.005). This retrospective
study did not have sufficient numbers of fatal cardiopulmonary complications to exclude the possibility that these may be
predicted by the results of this simple test.
Determination of the constituents of the radioactive ion beam (RIB) is crucial for successful experiments at low-energy RIB facilities and as such decides the fate of many experiments. Here we ...present the role of TITAN’s Multiple-Reflection Time-Of-Flight Mass Separator (MR-TOF-MS) and how it complements the present capabilities at ISAC-TRIUMF for yield determinations and beam delivery. This non-scanning, broadband, high-resolution mass spectrometer allows for real-time identification and quantification of all species, ranging from radionuclides with half-lives as low as a few ms to stable isotopes and molecules. In this manner it can be efficiently used to optimize RIB delivery through the ISAC mass separator for rate of the species of interest or its ratio to contamination. We present an example of this optimization approach, where the purity of secondary beams of neutron-rich titanium was improved by more than one order of magnitude based on the diagnostics capabilities of the new MR-TOF-MS and thus, allowed for high-precision mass measurements at TITAN.
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