We propose a large-area, cost-effective muon telescope detector (MTD) at mid-rapidity for the solenoidal tracker at the RHIC (STAR) and for the next generation of detectors at a possible electron-ion ...collider. We utilize large multi-gap resistive plate chambers with long readout strips (long-MRPC) in the detector design. The results from cosmic ray and beam tests show that the intrinsic timing and spatial resolution for a long-MRPC are 60-70 ps and ~1 cm, respectively. The performance of the prototype muon telescope detector at STAR indicates that muon identification at a transverse momentum of a few GeV/c can be achieved by combining information from track matching with the MTD, ionization energy loss in the time projection chamber and time-of-flight measurements. A primary muon over secondary muon ratio of better than 1/3 can be achieved. This provides a promising device for future quarkonium programs and primordial dilepton measurements at the RHIC. Simulations of the muon efficiency, the signal-to-background ratio of J/psi, the separation of 1S from 2S+3S states and the electron-muon correlation from charm pair production in the RHIC environment are presented.
A thin float glass MRPC for the outer region of CBM-TOF wall Weiping, Zhu; Yi, Wang; Shengqin, Feng ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2014, Letnik:
735
Journal Article
Recenzirano
A Multi-gap Resistive Plate Chamber (MRPC) made out of thin float glass is proposed for the outer region of the time of flight (TOF) system for the Compressed Baryonic Matter experiment at FAIR. ...Usually MRPCs are assembled with ordinary glass plates of 0.5 mm or more thickness, but their rate capability is less than the CBM requirement (1.5 kHz/cm2). There are two ways to improve the rate capability. The first way is to reduce the bulk resistivity of the glass plates. The second is to reduce the thickness of the glass plates. Tsinghua University has made significant progress in the development of low resistive glass and high rate MRPCs. In this paper we report on three MRPCs produced with float glass plates of 0.7 mm, 0.5 mm and 0.35 mm thickness. Tests with cosmic rays and X-rays were performed at Tsinghua University. The results show that thin float glass MRPCs work well and have the rate capability necessary to meet the demands of the CBM-TOF outer region. Further studies were performed using a continuous 1 GeV deuterium beam at the Nuclotron accelerator at the Joint Institute for Nuclear Research (JINR). Time resolution of about 70 ps and efficiency higher than 90% were obtained for flux densities up to 3 kHz/cm2, exceeding the requirement for the CBM-TOF outer region.
The performance of additive manufactured (AM) RF circuits and antennas is continuously improving, and in some cases these AM components are comparable to state-of-the-art circuits made with ...traditional manufacturing techniques. Medium to high-power waveguides made with AM methods such as copper-plated plastics, selective laser melting (SLM), and copper additive manufacturing (3-D CAM) have shown good performance up to terahertz frequencies. In this paper, binder jetting (BJ) metal printing is characterized using electron beam microscopy scanning electron microscopy (SEM) and energy dispersive spectroscopy. The RF performance of the 3-D-printed circuits is benchmarked with Ka-band cavity resonators, waveguide sections, and a filter. An unloaded resonator Q of 616 is achieved, and the average attenuation of the WR-28 waveguide section is 4.3 dB/m. The BJ technology is tested with a meshed parabolic reflector antenna, where the illuminating horn, waveguide feed, and a filter are printed in a single piece. The antenna shows a peak gain of 24.56 dBi at 35 GHz.
We report the timing and spatial resolution from the Muon Telescope Detector (MTD) installed in the STAR experiment at RHIC. Cosmic ray muons traversing the STAR detector have an average transverse ...momentum of 6GeV/c. Due to their very small multiple scattering, these cosmic muons provide an ideal tool to calibrate the detectors and measure their timing and spatial resolution. The values obtained were ~100ps and ~1–2cm. These values are comparable to those obtained from cosmic-ray bench tests and test beams.
The TOFp/pVPD time-of-flight system for STAR Llope, W.J; Geurts, F; Mitchell, J.W ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2004, Letnik:
522, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A time-of-flight system was constructed for the STAR Experiment for the direct identification of hadrons produced in
197Au+
197Au collisions at RHIC. The system consists of two separate detector ...subsystems, one called the Pseudo Vertex Position Detector (pVPD, the “start” detector) and the other called the Time of Flight Patch (TOFp, the “stop” detector). Each detector is based on conventional scintillator/phototube technology and includes custom high-performance front-end electronics and a common CAMAC-based digitization and read-out. The design of the system and its performance during the 2001 RHIC run will be described. The start resolution attained by the pVPD was 24
ps, implying a pVPD single-detector resolution of 58
ps. The total time resolution of the system averaged over all detector channels was 87
ps, allowing direct
π/
K/
p discrimination for momenta up to ∼1.8
GeV/
c, and direct (
π+
K)/
p discrimination up to ∼3
GeV/
c.
Direct digital manufacturing (DDM) is an emerging technology that is finding its place across a wide array of industries and applications as a cost-effective solution for low volume and mass ...customizable production. This technology encompasses a class of digital manufacturing techniques which can be combined to enable multimaterial fabrication and postprocessing. One of the promising applications for DDM is structural electronics, where lightweight printed plastics provide mechanical support as a fixture, package, or structural member and also host the electrical interconnects and devices, all in a contiguous fashion. Microwave structural electronics is a specific class of such systems for which the printing resolution as well as electrical and surface properties of the materials are especially important. This paper presents the current state of DDM technology, fundamental research into the electrical and mechanical properties of as-printed structures, and novel 3-D printed structures operating from C-band through Ku-band.
Performance of the prototype MRPC detector for STAR Geurts, F.; Shao, M.; Bonner, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2004, Letnik:
533, Številka:
1-2
Journal Article
Recenzirano
A prototype 168-channel multi-gap resistive plate chamber (MRPC) time-of-flight system for the STAR experiment at RHIC was completed in February 2002, tested for 10 weeks at the AGS at BNL, and ...installed in the STAR detector for the 2002–2003 physics run. At the AGS, the MRPC detectors were operated on a number of different gas mixtures, high voltages, and threshold voltages. The results for detection efficiency, time resolution, streamer probability, and noise rates are presented.
To describe a large single-center experience with hepatic resection for metastatic leiomyosarcoma.
Liver resection is the treatment of choice for hepatic metastases from colorectal carcinoma. In ...contrast, the role of liver resection for hepatic metastases from leiomyosarcoma has not been defined.
The records of 26 patients who between 1982 and 1996 underwent a total of 34 liver resections for hepatic metastases from leiomyosarcoma were reviewed. There were 23 first, 9 second, and 2 third liver resections. The records were analyzed with regard to survival and predictive factors.
In the 23 first liver resections, there were 15 R0, 3 R1, and 5 R2 resections. Median survival was 32 months after R0 resection and 20.5 months after R1/2 resection. The 5-year survival rate was 13% for all patients and 20% after R0 resection. In 10 patients with extrahepatic tumor at the time of the first liver resection, 6 R0 and 4 R2 resections were achieved. After R0 resection, the median survival was 40 months (range 5-84 months), with a 5-year survival rate of 33%. After repeat liver resection, the median survival was 31 months (range 5-51 months); after R0 resection, median survival was 31 months and after R1/2 resection it was 28 months. There was no 5-year survivor in the overall group after repeat liver resection.
Despite frequent tumor recurrence, the long-term outcome after liver resection for hepatic metastases from leiomyosarcoma is superior to that after chemotherapy and chemoembolization. Although survival after tumor debulking also seems to be more favorable than after nonoperative therapy, these data indicate that only an R0 resection offers the chance of long-term survival. The presence of extrahepatic tumor should not be considered a contraindication to liver resection if complete removal of all tumorous masses appears possible. In selected cases of intrahepatic tumor recurrence, even repeated liver resection might be worthwhile. In view of the poor results of chemoembolization and chemotherapy in hepatic metastases from leiomyosarcoma, liver resection should be attempted whenever possible.
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