Introduction to Charged Particles:
Bridging the Gap between Earth and Space
Marjan Moreels, PhD
Radiobiology Unit
Belgian Nuclear Research Center, SCK•CEN, Belgium
MELODI 2013, Brussels, Belgium
Oct 10, 2013 – Session ‘Heavy ions’
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Sources of Radiation Exposure
2.4 mSv/yr
WNA (2013)
 Different radiation qualities
 Low-energy particles (alpha, beta)
 Photons (γ-rays, X-rays)
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Exposure to high-energy charged particles
1. Natural
Occupational activities in space
2. Man-made
Cancer radiotherapy
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1. Natural exposure to charged particles
Dense ionization tracks (high RBE)
Maalouf et al., J Rad Res 52 (2011)
Main health risk for long-term space missions
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2. Man-made exposure to charged particles
 Particle accelerators
 Proton
 Carbon (high RBE, OER)
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Conditions
Space
Particle therapy
Source
Particle
Max
Energy
Dose
Exposure
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Conditions
Source
Space
Particle therapy
Galaxy - Sun
Particle accelerators
Particle
Max
Energy
Dose
Exposure
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Conditions
Space
Particle therapy
Source
Galaxy - Sun
Particle accelerators
Particle
All ions from H to Fe
H and C (Li, O, …)
Max
Energy
Dose
Exposure
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Conditions
Space
Particle therapy
Source
Galaxy - Sun
Particle accelerators
Particle
All ions from H to Fe
H and C (Li, O, …)
Max
Energy
~10 GeV/n
H: ~250 MeV/u
C: ~400 MeV/u
Dose
Exposure
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Conditions
Space
Particle therapy
Source
Galaxy - Sun
Particle accelerators
Particle
All ions from H to Fe
H and C (Li, O, …)
Max
Energy
~10 GeV/n
H: ~250 MeV/u
C: ~400 MeV/u
Dose
- ISS: 200-600 µSv/day
- Interplanetary: 1-2 mSv/day
(GCR: low dose - SPE: high dose)
- Round trip Mars: ~0.66 Sv
- Target: high (60-80 Gy-eq)
- Margin: high/low
- Surrounding tissue: low
(+problem of leakage neutrons!)
(Zeitlin et al., Science 340 (2013))
Exposure
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Conditions
Space
Particle therapy
Source
Galaxy - Sun
Particle accelerators
Particle
All ions from H to Fe
H and C (Li, O, …)
Max
Energy
~10 GeV/n
H: ~250 MeV/u
C: ~400 MeV/u
Dose
- ISS: 200-600 µSv/day
- Interplanetary: 1-2 mSv/day
(GCR: low dose - SPE: high dose)
- Round trip Mars: ~0,66 Sv
- Target: high (60-80 Gy-eq)
- Margin: high/low
- Surrounding tissue: low
(+problem of leakage neutrons!)
Chronic
Whole body
Acute
Partial body
(Zeitlin et al., Science 340 (2013))
Exposure
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Current concerns and uncertainties
about charged particles
…in the low dose range
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Carcinogenesis
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Carcinogenesis risk in space
 Charged particles have a higher carcinogenic effect than low-LET
 Main risk factor for astronauts
 Large uncertainties in cancer risk prediction
Durante & Cucinotta, Nature Rev 8 (2008)
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Secondary malignancies after particle therapy
 Long-term survivors of cancers after conventional RT
 10-20% of secondary malignancies 30 yrs after treatment
(Smith et al, J Clin Oncol 28 (2010); Friedman et al., J Natl Cancer Inst 102 (2010))
 Risks following particle therapy have not been determined
 Cancers can arise in the irradiation field (high dose) or in distal organs
(low-dose region) + (low dose) neutron leakage
 Need to develop risk assessment based on current knowledge of
radiation-induced carcinogenesis
 Impact of age – genetic susceptibility – radiation quality
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Charged particle research
@Radiobiology Unit of SCK•CEN
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Particle Research at SCK•CEN
 Fundamental research into biological actions of charged particles
 In vitro studies (normal + cancer cells)
 Hadron therapy for prostate cancer ( ppt Annelies Suetens)
 Biodosimetry & individual radiosensitivity (ESA IBER-3 GYMBRASS)
 Toxicity of normal tissues (cardiovascular– immune system)
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Let’s get started now…
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Thank you for your attention!
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PLEASE NOTE!
This presentation contains data, information and formats for dedicated use ONLY and may not be copied,
distributed or cited without the explicit permission of the SCK•CEN. If this has been obtained, please reference it
as a “personal communication. By courtesy of SCK•CEN”.
SCK•CEN
Studiecentrum voor Kernenergie
Centre d'Etude de l'Energie Nucléaire
Belgian Nuclear Research Centre
Stichting van Openbaar Nut
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Foundation of Public Utility
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(Neuro)degenerative diseases
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Neurodegenerative changes

Light flash phenomenon

Particle interaction with retinal photoreceptors
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