1. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 MEASUREMENT OF PROTON ELASTIC SCATTERING CROSS SECTIONS FOR LIGHT ELEMENTS – VALIDATION OF A “BULK SAMPLE” METHOD. A.R. Ramos, N.P. Barradas, E. Alves

2. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 OUTLINE Objectives Equipment Proposed plan Samples Measurements: “thin film” and bulk samples

3. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 Objectives Measurement of (p,p) elastic scattering cross sections for nitrogen and lithium in the 500-2500 keV energy range. (p,p) cross sections for N to be measured using the standard ”thin film” technique. Measurement will span the 500-2500 keV energy range and scattering angles between 160º, 150º and 130º, complementing existing data. (p,p) cross sections for Li to be measured using a thick film target or bulk sample. The method will first be validated using the measured cross-sections for nitrogen and the existing evaluated cross sections for oxygen and silicon.

4. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 ITN - Equipment 2.5 MV Van de Graaff accelerator, equipped with microprobe 210 kV high fluence implanter

5. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 Proposed Plan Tasks to be performed by order of execution: 1.Procurement of appropriate thin film and bulk samples for cross section measurements. 2.Detailed compositional analysis of the samples by PIXE and RBS. 3.Measurement of the (p,p) cross section for N using the “thin film technique”. 4.Development and validation of a “bulk sample” method for proton elastic scattering cross-section measurements using the measured N cross-sections and the evaluated O and Si cross sections. 5.Application of the “bulk sample” method to the measurement of the proton elastic cross section for lithium.

6. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 Samples Thin films: Au/AlN/C Bulk samples: TiO 2, Si, Si(Sb), LiF + ?

7. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 “Thin film” Measurements-N(p,p)N Figure 1:  =160º PRELIMINARY!

8. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 “Thin film” Measurements-N(p,p)N Figure 2:  =130º PRELIMINARY!

9. Rita Ramos ariel@itn.pt IBA RCM, 21-23 Nov 2005 “Bulk” Measurements - Li(p,p)Li Measure bulk samples at different beam energies. Fit results with cross section as fit parameter. Validate method with N, Si and O. Then apply to Li.