Double differential distribution of electron emission in the ionization of water molecules by fast bare oxygen ions

Abstract

The doubly differential distributions of low-energy electron emission in the ionization of water molecules under the impact of fast bare oxygen ions with energy of 48 MeV are measured. The measured data are compared with two quantum-mechanical models, i.e. the post and prior versions of the continuum distorted wave-eikonal initial state (CDW-EIS) approximation, and the first-order Born approximation with initial and final wavefunctions verifying correct boundary conditions (CB1). An overall excellent qualitative agreement is found between the data and the CDW-EIS models whereas the CB1 model showed substantial deviation. However, the detailed angular distributions display some discrepancies with both CDW-EIS models. The single differential and total cross-sections exhibit good agreement with the CDW-EIS models. The present detailed data set could also be used as an input for modeling highly charged ion induced radiation damage in living tissues, whose most abundant component is water. Similar measurements are also carried out for a projectile energy of 60 MeV. However, since the double differential cross-section data show similar results the details are not provided here, except for the total ionization cross-sections results.

Non-perturbative scaling behavior for net ionization of biologically relevant molecules by multiply-charged heavy-ion impact

“…For Q = 3 (shown in green) there is agreement with the Li 3+ experimental data con- [16], circles [46], triangles [19], diamonds [18]; Q = 2 shown as blue solid squares [16], circles [17], open diamonds [47]; Q = 3 shown as green solid triangles [20]; Q = 6 shown as open red circles (6 MeV/amu): [48], (4 MeV/amu): [23]; Q = 8 shown as open purple triangles [22,24]; and Q = 13 shown as an open magenta square [23].…”

“…O 8+ [22,24], and Si 13+ [23] is very satisfactory with some tension with the O 8+ data. Overall we find that the proposed IAM-PCM scaling with projectile charge and energy works well for the water molecule target and is strongly supported by experiment for medium to high In Fig.…”

“…Experimental data for charged-particle impact with Q = 1, 2, 3 on water molecules have been obtained for a wide range of collision energies [16][17][18][19][20]. For higher charges Q measurements are available at higher collision energies [21][22][23][24] in the form of differential electron emission cross sections together with CDW-EIS theory, and integration of the differential data determines total ionization cross sections.…”

Single-Capture Cross Sections from Biological Molecules and Noble Gases by Bare Ion Impact

“…The obtained results are in reasonable agreement with the experimental findings. Previous calculations of doubly differential, single differential, and total cross sections for water vapor and DNA nucleobases have been done using the CDW-EIS and first Born approximation with correct boundary conditions (CB1) [30][31][32][33]. Later, Quinto et al [34] have calculated the differential and total cross sections for single-ionization and single-electron capture from biological molecules by bare projectile impact of energies ranging from 50 to 10,000 keV/amu using the CDW-EIS method.…”

SCENA: A simulation tool for radiation-induced gas scintillation

“…The HKS-computed data obtained with SCENA are denoted with lines. The experimental data references are: 1 MeV proton in argon from Rudd et al [27], 72 MeV bare carbon ion in water vapor from Champion [40], 48 MeV oxygen ion in water vapor from Bhattacharjee et al [44], and ssion fragments in helium from Dyachenko [41]. For that combination, an average-like ssion fragment is used.…”