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Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna. Track Core Size of Proton and Heavy Ions in PADC Detectors Tomoya Yamauchi Kobe University, Japan. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid.

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Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

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  1. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Track Core Size of Proton and Heavy Ions in PADCDetectorsTomoya YamauchiKobe University, Japan Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  2. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Tomoya YAMAUCHI, Yutaka MORI, Keiji ODA,Kobe University, Graduate School of Maritime Sciences, 5-1-1 Fukaeminami-machi, Kobe, Japan.Nakahiro YASUDA,National Institute of Radiological Science, 4-9-5 Anagawa, Inage-ku, Chiba, Japan.Rémi BARILLON,Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, Strasbourg, France.アンスティチュート・プリュリィディシプリネール・ユベール・キュイア Organization Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  3. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Outline of the present study • Motivation & Purpose • Tracks in PADC • UV-method: UV-visible absorption spectra, Track overlapping model (core size) • AFM-Method: Surface observation by Atomic Force Microscope after short-time etching (core size) • IR-method: Fourier transform-IR absorption spectra, G value (chemical modification) • Summary Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  4. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Motivation & Purpose • For the development of new SSNTDs: with higher sensitivity: 5 keV/µm >>> 0.5 keV/µm, with controllable detection thresholds. • To elucidate the track structure and track formation process in PADC and other polymers Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  5. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Materials • PADC: poly(allyl diglycol carbonate)  BRYOTRAK (Fukuvi Chemical Industry) / CR-39 • PC: Bisphenol A polycarbonate Macrofol KG (Good fellow) Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  6. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna What is track core? In some physical models, track core is treated as the region where theprimary or direct ionization is dominant,surrounded by the track halo or penumbra,that is produced by the secondary electrons or delta-rays.In this work,…… Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  7. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna What is track core? Track core size by three different ways:1) UV-method: optically modified region due to the creation of some types of damage2) AFM-method: region where the local etching rate is significantly enhanced3) IR-method: region where carbonate ester bonds and ether bonds are lost Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  8. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method UV-Visible absorption spectra of PADC Fig. 1 UV-Visible spectra of a PADC sheet and the monomer. Fig. 2 UV-Visible-Near IR spectra of a PADC sheet. C=O carbonyl 2751 nm: 3635 cm-1 : H2O anti-symmetric 2820 nm: 3550 cm-1 : OH, H2O symmetric 2880 nm: 3470 cm-1 : C=O the first overtone Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  9. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Irradiations were carried out using a tandem Van de Graaff accelerator at Graduate School of Maritime Sciences, Kobe University.Table 1. Irradiation condition. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  10. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method UV-Visible spectra of PADC sheets exposed to energetic protons in vacuum 1st  2nd  1st  2nd  Fig. 3 UV-Visible spectra of PADC sheets exposed to 3.4 MeV proton beams. Fig. 4 UV-Visible spectra of PADC sheets exposed to 3.4 MeV proton beams at higher fluences. The first peak is at 240 nm and the second one is at 280 nm. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  11. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Dependence of the peak height and peak height ratio on proton fluence: 280nm/240nm Fig. 5 Changes in the absorbance at the first and the second peaks with proton fluence. Fig. 6 Changes in the peak height ratio with proton fluence. The height of 1st peak decreased around 2.5x1013 ions/cm2 .The proportionality was lost at 1.0x1013 ions/cm2 . Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  12. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Track overlapping and UV absorption spectra Fig. 7 Without track overlapping, the optical density should be simply doubled when the fluence is doubled. Tracks are assumed to be simple cylinders. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  13. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Track piling (random number):track radius = 3.5 nm 100 nm Fig. 8 Evolution of track piling with fluence (simulation). Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  14. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Pileup of tracks (model) Drops of rain Les feuilles mortes Fig. 9 Evolution of track overlapping at various track radii. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  15. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Critical fluence where the overlapping becomes significant Fig. 11 Relation between the critical fluence and track radius. Fig. 10 Evolution of track overlapping with fluence. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  16. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Track core radius versus stopping power Fig. 12 Relation between the track core radii and stopping power from the UV method . NIM B 208 (2003)149-154. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  17. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method HIMAC for heavier ionsHeavy Ion Medical Accelerator in Chiba Table 2. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid Port Plaza Chiba HIMAC共同利用研究成果発表会

  18. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Track core radius versus stopping power Fig. 13 Relation between the track core radii and stopping power from the UV method (HIMAC). NIM B 236 (2005)318-322. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  19. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna UV-method Track core radius by UV-method Fig. 14 Relation between the track core radii and stopping power from the UV method. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  20. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna AFM-method Track core radius offission fragments by AFM Fig. 16 Evolution of minute etch pit of fission fragments in the subsurface layer. The intersection on the coordinate indicates the core radius of fission fragments of about 6 nm. RM 37 (2003)119-125. Fig. 15 Typical AFM images of etched PADC. The samples were etched in 6 M KOH solution at 70 ºC for 2 min (a) and 50 s (b). Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  21. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna AFM-method Table 3. HIMAC and VIVITRON (Strasbourg) Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  22. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna AFM-method Track core radius by AFM-method Fig. 17 Etch pits of Fe ion.Etching time: 60 s. Fig. 18 Evolution of minute etch pit of heavy ions. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  23. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna AFM-method Track core radius versus stopping power Track core radii from the AFM method are greater than those from the UV methods for relatively heavier ions. Fig. 19 Relation between the track core radii and stopping power from the AFM and UV methods. Rev FMS.KU 2 (2006)179-184. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  24. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna IR-method FT-IR spectra of PADC Fig. 20 FT-IR spectra of PADC films with various thickness. Fig. 21 Changes in absorbance for some bands of PADC with film thickness. Beer-Lambert law Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  25. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna IR-method Loss of carbonyl along tracks in PADC Fig. 22 Spectral change of PADC in IR region by Fe ion irradiation. Fig. 23 Decrease of carbonate ester bonds with heavy ion fluence. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  26. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna IR-method Track core radius by IR-method Fig. 24 Relation between the track core radii and stopping power from the IR-method (GANIL&HIMAC). Fig. 25 Relation between the track core radii and stopping power from the IR-method (HIMAC). RM 40 (2005)224-228. RM 43 (2008)S106-S110. JJAP 47 (2008)3606-3609. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  27. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Track core radius by UV, AFM and IR methods Fig. 26 Relation between the track core radii and stopping power from the three methods. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  28. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Track core radius by UV, AFM and IR methods Fig. 27 Relation between the track core radii and stopping power from the three methods. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  29. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Track core radius and G value (1/3) Experimentally obtained relation: Where F is fluence. At a fluence of 1 ion/cm2, This indicates the number of decreased bond per unit length of one track, i.e. damage density, L: Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  30. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Track core radius and G value (2/3) G value is attained by dividing L by the average stopping power in films, . If the track core radius is proportional to the square root of stopping power, G value was independent of the stopping power, as: Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  31. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Track core radius and G value (3/3) Fig. 28 Relation between the track core radii and stopping power. Fig. 29 Relation between G value and stopping power. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  32. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Tracks in PADC by UV method Fig. 30 Relation between the track core radii and stopping power in PADC. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  33. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Tracks in PADC Fig. 30 Relation between the track core radii and stopping power in PADC. Fig. 31 Relation between the G value for loss of C=O and stopping power in PADC (1). Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  34. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna discussion Tracks in PADC Fig. 30 Relation between the track core radii and stopping power in PADC. Fig. 32 Relation between the G value for loss of C=O and stopping power in PADC (2). G value = 17 (/100eV) for gamma-ray !! Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  35. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Summary 1/2 Higher G values at lower stopping power in PADC not in PC Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  36. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Summary 2/2 Good selections of the molecule structure between two carbonate ester bonds can provide us sufficient polymers for SSNTDs. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  37. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Thank you for your attention!Grazie! Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  38. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna G value: ICRU report 60, 1998Fundamental Quantities and Units for Ionizing Radiation • The radiation chemical yield, G(x), of an entity, x, is the quotient of n(x) by , where n(x) is the mean amount of substance of that entity produced, destroyed, or changed in a system by the energy imparted, , to the matter of that system, thus, Unit: mol J-1 The related quantity, called G value, has been defined as the number of entities produced, destroyed or changed by an energy imparted of 100 eV. The unit in which the G value is expressed is (100 eV)-1. A G value of 1 (100 eV)-1 corresponds to a radiation chemical yield of 0.104 µmol J-1. ICRU: International Commission on Radiation Units and Measurements Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  39. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Occupied area by tracks: A(n)at fluence of n (ions/cm2), track area of s ProbabilityA(n-1) fall into the occupied area1-A(n-1)fall into the non-occupied area Fig. 10 Fraction of the occupied area by tracks. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  40. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna N-folds area by tracks: AN(n) Poisson distribution Fig. 11 Evolution of track overlapping with fluence. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  41. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Determination of the critical fluences for He and C Fig. 13 Changes in the absorbance at the first and the second peaks with helium ion fluence. Fig. 14 Changes in the absorbance at the first and the second peaks with carbon ion fluence. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  42. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Determination of the critical fluences Fig. 15 Changes in the absorbance at the first and the second peaks with oxygen ion fluence. Fig. 16 Changes in the peak height ratio with ion fluence. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  43. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna AFM-method without etching Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid Tracks of 80 MeVAu ion in PMMA

  44. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna AFM-method OLYMPUS NanoVision 2000 Fig. 21 Etch pit radii for fission fragments and alpha-particles as a function of the etching time. Fig. 23 Assessed latent track radial size in PADC plastics for light ions and fission fragment indicating as a function of stopping power. RM 37 (2003)119-125. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  45. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Track core radius by IR-method Fig. 31 Relation between the track core radii and stopping power from the IR-method (GANIL&HIMAC). GANIL: Grand Accelerateur National d’Ions Lourds Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  46. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Track core radius in PC Fig. 33 Relation between the track core radii and stopping power in PC from various methods. Rev FMS.KU 4 (2006)61-70. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  47. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Tracks in PC Fig. 34 Relation between the track core radii and stopping power in PC. Fig. 35 Relation between the G value for loss of C=O and stopping power in PC. Almost independent of stopping power Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  48. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Tracks in PADC Fig. 41 Radial dose distribution of energy deposited around the path of heavy ions in PC. Fig. 42 Radial dose distribution of energy deposited around the path of heavy ions in PADC. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  49. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Gamma-irradiated PADC Fig. 41 Decrease of the relative absorbance with gamma-dose. Fig. 42 G value for loss of carbonate ester bonds in gamma and heavy ion irradiated PADC. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

  50. 24th International Conference on Nuclear Tracks in Solids 1 - 5 September 2008, Bologna Summary 1/3 • A review was given for the present status of our study on track core radii for proton and heavy ions in PADC. • Evaluated core radii were dependent on the methods: UV, AFM, and IR-methods. Bologna, 2008 24th Int. Conf. Nuclear Tracks in Solid

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