Standard Practice for Dosimetry of Proton Beams for use in Radiation Effects Testing of Electronics

Representatives of facilities that routinely deliver protons for radiation effect testing are collaborating to establish a set of standard best practices for proton dosimetry. These best practices will be submitted to the ASTM International for adoption

FLUKA Monte Carlo assessment of the terrestrial muon flux at low energies and comparison against experimental measurements

In recent years, there has been an increasing interest in the assessment and modelling of Galactic Cosmic Rays (GCR) particularly regarding the evaluation of the radiation effects on airline crew and passengers, interplanetary missions and on-board microelectronics. In the latter field, today the problem is not just limited to Single Event Effects (SEE) as used in avionics, but is more and more observed at ground level. Galactic cosmic muons, coming from the interaction of primary cosmic rays in the Earth's atmosphere, represent the most numerous species at ground level. In this work, we used the Monte Carlo code FLUKA to assess the atmospheric and terrestrial neutron and muon differential fluxes at various altitudes and specific examples such as the geographic coordinates corresponding to New York City and Vancouver. In this context, particle energy spectra were compared with references available in literature, calculation results obtained by both the QARM and EXPACS codes, as well as recently performed measurements. In addition, the zenith angular distribution, at ground level, was assessed for both neutrons and muons and compared with available references. Differential particle fluxes assessed for Vancouver were used as a primary source to simulate a muon detector currently taking data at TRIUMF to evaluate the passing and stopping terrestrial muon rate under different conditions. Finally, simulations were compared with the experimental measurements made at TRIUMF. Results show an excellent agreement between the FLUKA simulations and both references and the experimental measurements made at TRIUMF

TRIUMF brown reports TRI-69-1

Electric v(vector) x B(vector) dissociation of H⁻ ions moving through a magnetic field has been measured for electric field strengths near 2 MV/cm. The H⁻ ions were obtained by charge exchange of protons in water vapour and were accelerated to 49.5 MeV by the proton linear accelerator at the Rutherford High Energy Laboratory. Stripped particles were detected using an acoustic spark-chamber. Experimental lifetimes are lower by approximately a factor of two from those predicted by Mullen ¹) and a factor of three from those predicted by Hiskes ²). Our measurements also appear inconsistent with those of Cahill et al. ³).TRIUMFNon UBCUnreviewedResearche

SEL Cross Section Energy Dependence Impact on the High Energy Accelerator Failure Rate

We use a single event latchup (SEL) model calibrated to heavy ion (HI) and proton data below 230 MeV to extrapolate the proton cross section to larger energies and evaluate the impact of the potential cross section increase with energy on the SEL rate in different environments. We show that in the case of devices with a large LET onset for HI and a certain amount of tungsten near the sensitive volume (SV), the calculated failure rates for energetic environments based on monoenergetic test data can significantly underestimate the real value. In addition, we show through measurements using a 480 MeV beam and an inspection of the device’s architecture that the model was successful in estimating the SEL cross section and tungsten volume per cell

Progress report on the feasibility of using the ISR magnets in a TRIUMF Kaon factory

TRIUMF is considering the construction of a "kaon factory" post-accelerator to take the present 100 ~ proton beam (6 x 10¹⁴ p/s) f rom 500 MeV to energies in the tens of GeV. This would provide beams of kaons, antiprotons, neutrinos, etc., 100-1000 times more intense - or alternatively cl eaner - than those available at present. Such beams would open up new fields in both nuclear and particle physics in the same way that the pion factories LAMPF, SIN and TRIUMF have done at lower energies; in particular the enhanced ability to study rare processes could throw light on mass regions far beyond those accessible with any presently conceivable super-high energy accelerator. Since it is understood that there are no definite plans to use the dipole magnets from the Intersecting Storage Rings at CERN af t er closure of the ISR in 1984, a study has been undertaken to assess the feasibility of incorporating them in a TRIUMF kaon factory. If these magnets were available at nominal cost, then for the same total funds it should be possible to build a kaon factory of considerably higher energy and physics capability. Out of various options the one selected as most suitable in terms of its physics capability, site requirements and cost would use one ring of magnets for a 30 GeV 50 ~ synchrotron and the other for a 30 GeV dc stretcher ring.. The magnets would be reconfigured in a regular 48 cell FFODDO lattice, apart from 4 straight sections. The two rings would be mounted one above the other in the same tunnel, along with a dc accumulator ring at the injection energy. This arrangement would have the advantage of providing both low and high duty factor beams from the outset. The synchrotron magnets would operate with a triangular waveform at 0.5 Hz, using flywheel/motor generator energy storage. In the longer term a 60 GeV superferric or 120 GeV superconducting ring could be added in the tunnel.TRIUMFUnreviewedResearche