Shielding against galactic cosmic rays.

Ions of galactic origin are modified but not attenuated by the presence of shielding materials. Indeed, the number of particles and the absorbed energy behind most shield materials increases as a function of shield thickness. The modification of the galactic cosmic ray composition upon interaction with shielding is the only effective means of providing astronaut protection. This modification is intimately connected with the shield transport properties and is a strong function of shield composition. The systematic behavior of the shield properties in terms of microscopic energy absorption events will be discussed. The shield effectiveness is examined with respect to conventional protection practice and in terms of a biological endpoint: the efficiency for reduction of the probability of transformation of shielded C3H10T1/2 mouse cells. The relative advantage of developing new shielding technologies is discussed in terms of a shield performance as related to biological effect and the resulting uncertainty in estimating astronaut risk.

[1]  S. C. Sharma,et al.  Inactivation of cells by heavy ion bombardment. , 1971, Radiation research.

[2]  O. C. Allkofer,et al.  Measurements of cosmic ray heavy nuclei at supersonic transport altitudes and their dosimetric significance. , 1974, Health physics.

[3]  F. Cucinotta,et al.  Cell Kinetics and Track Structure , 1993 .

[4]  W Schimmerling,et al.  Radiobiological problems in space , 1992, Radiation and environmental biophysics.

[5]  Icrp.  1990 Recommendations of the International Commission on Radiological Protection , 1991 .

[6]  John W. Norbury,et al.  Transport Methods and Inter-actions for Space Radiations , 2003 .

[7]  C A Tobias,et al.  Neoplastic cell transformation by heavy charged particles. , 1985, Radiation research. Supplement.

[8]  F. Cucinotta,et al.  HZE Reactions and Data-Base Development , 1993 .

[9]  D. T. Goodhead,et al.  Transmission of chromosomal instability after plutonium α-particle irradiation , 1992, Nature.

[10]  D. Goodhead,et al.  Induction of sister chromatid exchanges (SCE) in G0 lymphocytes by plutonium-238 alpha-particles. , 1988, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[11]  J. Wilson,et al.  NUCFRG2: a semiempirical nuclear fragmentation model. , 1994, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms.

[12]  J. Hendry,et al.  Alpha particles are extremely damaging to developing hemopoiesis compared to gamma irradiation. , 1994, Radiation research.

[13]  A. Wambersie,et al.  Introduction to Radiobiology , 1990 .

[14]  C. Tobias,et al.  Neoplastic cell transformation by high-LET radiation: molecular mechanisms. , 1989, Advances in space research : the official journal of the Committee on Space Research.

[15]  Francis A. Cucinotta,et al.  Depth-dose equivalent relationship for cosmic rays at various solar minima. , 1993, Radiation research.

[16]  P. Schonken,et al.  Health effects of exposure to low levels of ionizing radiation , 1991 .

[17]  J. Howard,et al.  The propagation of relativistic heavy ions in multielement beam lines. , 1986, Medical physics.

[18]  Schaefer Hj.  Evaluation of present-day knowledge of cosmic radiation at extreme altitude in terms of the hazard to health. , 1950 .

[19]  G. Horneck,et al.  Biological Effects and Physics of Solar and Galactic Cosmic Radiation , 1993, NATO ASI Series.

[20]  C. Lushbaugh.  Guidance on Radiation Received in Space Activities , 1990 .