| 1. |
- Pinsky, L., et al.
(författare)
-
Measurement of Fragmentation Products including Angular Distributions for 3, 5, and 10 GeV/A C and Si on several nuclear targets at the AGS
- 2010
-
Ingår i: 2009 12th International Conference on Nuclear Reaction Mechanisms, NRM 2009; Varenna; Italy; 15 June 2009 through 19 June 2009. - 2078-8835. - 9789290833413 ; 2, s. 431-437
-
Konferensbidrag (refereegranskat)abstract
- Motivated by differences in the predicted fragmentation of heavy ions at energies around 5 GeV/A as employed in the event generators used by the FLUKA Monte Carlo Code [1], a set of measurements were carried out at the AGS facility at the Brookhaven National Laboratory to determine as much information as possible about the cross sections to allow harmonization of those event generators for these incident lab energies. The FLUKA Code employs the RQMD event generator of Sorge [2] for heavy ion interactions starting at 100 MeV/A and extending into the region around 5 GeV/A. Above those energies the DPMJET code of Ranft and Roesler [3] is typically employed to simulate such interactions. The detailed predictions of these event generators had some disagreement in the vicinity of this crossover energy and in order to tune these codes to be in closer harmony at the transition, and of course to be simulating nature as closely as possible, data were taken at 3, 5 and 10 GeV/A with beams of Fe, Si and C on a variety of targets including C, A1. Fe and Cu. The Fe data have not been fully analyzed, but results from the C and Si beams are available and the forward fragment spectrum along with a measurement of the charged particle angular distribution in a set of Si strip detectors out to about 45 degrees in the lab are available. These include sufficient statistics to provide the charged particle distributions as a function of the major projectile fragment. The detectors used in this measurement were based on what were reasonably available to us, and as such were limited in capability, and required separate data acquisition systems. Nevertheless, spectra were obtained that should be sufficient to enable the harmonization of the event generator codes at the crossover energy. This paper discusses only the experimental results and not the impact of those results on the FLUKA code.
|
|
| 2. |
- Sihver, Lembit, 1962, et al.
(författare)
-
Simulations of MATROSHKA experiments at ISS using PHITS
- 2010
-
Ingår i: 12th International Conference on Nuclear Reaction Mechanisms, NRM 2009; Varenna; Italy; 15 June 2009 through 19 June 2009. - 2078-8835. - 9789290833413 ; 2, s. 553-560
-
Konferensbidrag (refereegranskat)abstract
- Concerns about the biological effects of space radiation are increasing rapidly due to the perspective of long-duration manned missions, both in relation to the International Space Station (ISS) and to manned interplanetary missions to Moon and Mars in the future. As a preparation for these long duration space missions it is important to ensure an excellent capability to evaluate the impact of space radiation on human health in order to secure the safety of the astronauts/cosmonauts and minimize their risks. It is therefore necessary to measure the radiation load on the personnel both inside and outside the space vehicles and certify that organ and tissue equivalent doses can be simulated as accurate as possible. In this paper we will present simulations using the three-dimensional Monte Carlo Particle and Heavy Ion Transport code System (PHITS) of long term dose measurements performed with the ESA supported experiment MATROSHKA (MTR), which is an anthropomorphic phantom containing over 6000 radiation detectors, mimicking a human head and torso. The MTR experiment, led by the German Aerospace Center (DLR), was launched in January 2004 and has measured the absorbed dose from space radiation both inside and outside the ISS. In this paper preliminary comparisons of measurements outside the ISS will be presented. The results confirm previous calculations and measurements which indicate that PHITS is a suitable tool for estimations of dose received from cosmic radiation and when performing shielding design studies of spacecraft.
|
|
| 3. |
- Lundquist, J. S., et al.
(författare)
-
MACHINE LEARNING METHODS FOR SINGLE SHOT RF TUNING
- 2021
-
Ingår i: 10th International Beam Instrumentation Conference, IBIC 2021 - Proceedings. - 2078-8835. - 9783954502301 ; , s. 313-316
-
Konferensbidrag (refereegranskat)abstract
- The European Spallation Source, currently under construction in Lund, Sweden, will be the world’s most powerful neutron source. It is driven by a proton linac with a current of 62.5 mA, 2.86 ms long pulses at 14 Hz. The final section of its normal-conducting front-end consists of a 39 m long drift tube linac (DTL) divided into five tanks, designed to accelerate the proton beam from 3.6 MeV to 90 MeV. The high beam current and power impose challenges to the design and tuning of the machine and the RF amplitude and phase have to be set within 1% and 1◦ of the design values. The usual method used to define the RF set-point is signature matching, which can be a challenging process, and new techniques to meet the growing complexity of accelerator facilities are highly desirable. In this paper we study the use of ML to determine the RF optimum amplitude and phase, using a single pass of the beam through the ESS DTL1 tank. This novel method is compared with the more established methods using scans over RF phase, providing similar results in terms of accuracy for simulated data with errors. We also discuss the results and future extension of the method to the whole ESS DTL.
|
|
| 4. |
- Sihver, Lembit, 1962, et al.
(författare)
-
PHITS - Applications to radiation biology and radiotherapy
- 2013
-
Ingår i: 13th International Varenna Conference on Nuclear Reaction Mechanisms, NRM 2012. - 2078-8835. - 9789290833826 ; , s. 497-502
-
Konferensbidrag (refereegranskat)abstract
- PHITS is a 3-dimensional general-purpose Monte Carlo code, which can transport of all varieties of hadrons and heavy ions with energies up to around 100 GeV/nucleon. To be able to estimate the biological damage from neutrons with PUTTS, a feature has been included to treat low energy neutron collisions as "events" which means that the energy and momentum is conserved in each event and makes it possible to extract the kinetic energy distributions of all the residual nuclei without using any local approximation. To estimate the direct biological effects of radiation, mathematical functions, for calculating the microdosmetric probability densities in macroscopic material, have been incorporated in PUTTS. This makes it possible to instantaneously calculate the probability densities of lineal and specific energies around the trajectories of high energetic charged particle tracks. A method for estimating the biological dose has also been established by using the improved PUTTS coupled to a microdosimetric kinetic model.
|
|
