| 1. |
- Clement, H, et al.
(författare)
-
Search for narrow NN-decoupled resonances in the pi NN-system - An overview
- 1996
-
Ingår i: PROGRESS IN PARTICLE AND NUCLEAR PHYSICS. - : PERGAMON PRESS LTD. ; , s. 369-378
-
Konferensbidrag (refereegranskat)abstract
- The status of the search for NN-decoupled resonances in the pi NN-system is reviewed. After a short survey on the history of dibaryon searches reactions suitable for detecting such resonances are discussed. Special emphasis is put on the pionic double cha
|
|
| 2. |
- Clement, H., et al.
(författare)
-
Search for narrow NN-decoupled resonances in the πNN-system : An overview
- 1996
-
Ingår i: Progress in Particle and Nuclear Physics. - : Elsevier BV. - 0146-6410 .- 1873-2224. ; 36, s. 369-378
-
Tidskriftsartikel (refereegranskat)abstract
- The status of the search for NN-decoupled resonances in the πNN-system is reviewed. After a short survey on the history of dibaryon searches reactions suitable for detecting such resonances are discussed. Special emphasis is put on the pionic double charge exchange, where recently evidence for the signature of a narrow πNN resonance, called d′, with I(J P) = even (0 -) and m = 2.06 GeV has been quoted. Further reactions discussed in this context are the pion photoproduction on the deuteron and the two-pion production in nucleon-nucleon collisions.
|
|
| 3. |
|
|
| 4. |
- Vatnitsky, S, et al.
(författare)
-
Proton dosimetry intercomparison
- 1996
-
Ingår i: Radiotherapy and Oncology. - 0167-8140 .- 1879-0887. ; 41:2, s. 169-77
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Methods for determining absorbed dose in clinical proton beams are based on dosimetry protocols provided by the AAPM and the ECHED. Both groups recommend the use of air-filled ionization chambers calibrated in terms of exposure or air kerma in a 60Co beam when a calorimeter or Faraday cup dosimeter is not available. The set of input data used in the AAPM and the ECHED protocols, especially proton stopping powers and w-value is different. In order to verify inter-institutional uniformity of proton beam calibration, the AAPM and the ECHED recommend periodic dosimetry intercomparisons. In this paper we report the results of an international proton dosimetry intercomparison which was held at Loma Linda University Medical Center. The goal of the intercomparison was two-fold: first, to estimate the consistency of absorbed dose delivered to patients among the participating facilities, and second, to evaluate the differences in absorbed dose determination due to differences in 60Co-based ionization chamber calibration protocols.MATERIALS AND METHODS: Thirteen institutions participated in an international proton dosimetry intercomparison. The measurements were performed in a 15-cm square field at a depth of 10 cm in both an unmodulated beam (nominal accelerator energy of 250 MeV) and a 6-cm modulated beam (nominal accelerator energy of 155 MeV), and also in a circular field of diameter 2.6 cm at a depth of 1.14 cm in a beam with 2.4 cm modulation (nominal accelerator energy of 100 MeV).RESULTS: The results of the intercomparison have shown that using ionization chambers with 60Co calibration factors traceable to standard laboratories, and institution-specific conversion factors and dose protocols, the absorbed dose specified to the patient would fall within 3% of the mean value. A single measurement using an ionization chamber with a proton chamber factor determined with a Faraday cup calibration differed from the mean by 8%.CONCLUSION: The adoption of a single ionization chamber dosimetry protocol and uniform conversion factors will establish agreement on proton absorbed dose to approximately 1.5%, consistent with that which has been observed in high-energy photon and electron dosimetry.
|
|
