1. Yury Gurchin June 2011 MEASUREMENT OF THE CROSS-SECTION IN DP-ELASTIC SCATTERING AT THE ENERGIES OF 500 AND 880 MEV AT NUCLOTRON

2. Here comes your footer Page  2  The purpose of DSS (Deuteron Spin Structure) project is broadening of energy and angular ranges of measurement of different variables in processes including 3-nucleon systems. The main aim of offered experiment program is extraction of information from spin depending part of 3-nucleon forces.  DSS project experimental program includes 2 experiments, one of them is the experiment of dp-elastic scattering study. During it will be done measurement of cross-section, vector A y, tensor A yy and A xx analyzing powers in dp-elastic scattering in the range of 300 and 1000 MeV of the deuteron kinetic energy.  The goal for the nearest runs is to measure the cross-section of dp-elastic scattering reaction in wide deuteron energy range with the step not more than 100 MeV in the region from 500-1000 MeV. This is needed for an experiment to measure analyzing powers for the dp-elastic scattering. DSS project The main aim of present investigation is to measure the cross-section of dp-elastic scattering at the energies of 500 and 880 MeV using kinematical coincidences of deuteron and proton with simple plastic scintillation counters and CH 2 and C targets at the internal target station at the Nuclotron.

3. Here comes your footer Page  3 Internal Target Station target beam

4. Here comes your footer Page  4 Scheme of the experiment PP-L PP-R D P M 1-6 Horizontal plane Vertical plane Beam P and D - proton and deuteron detectors (dp- elastic scattering) PP-L and PP-R –proton detectors (pp-quasi elastic scattering) M 1-6 - monitor counters.

5. Here comes your footer Page  5 Experimental setup at the Internal Target Station Internal target Detector’s base P and D detector Beam Photomultiplier FEU-85 PMT base Hull Scintillator Scintilator’s cover Counter # 2 for P and D detectors -Scintillators: 1) 20*25*5 mm or 10*25*5mm (counter #1) 2) 20*25*20 mm (counter #2)

6. Here comes your footer Page  6 Data handling The results obtained at 880MeV deuteron beam on polyethylene target: a) deuteron energy losses, b) proton energy losses, c) correlation of proton and deuteron energy losses, d) time difference between the signals for deuteron and proton detectors. CH 2 DATA 880MeV Proton energy losses Deuteron energy losses Deuteron energy losses (channels) Proton energy losses (channels) Deuteron energy losses (channels) Proton energy losses (channels) N events Deuteron & Proton energy losses Deuteron-Proton TOF Deuteron-Proton TOF (channels)

7. Here comes your footer Page  7 Data handling N events TDC SPECTRA FITTING TDC (Channels) Gauss+Const fit MPV - 4*SigmaMPV + 4*Sigma TDC spectra with gates 880 MeV СН2 target 60 deg. c.m. deuteron scattering

8. Here comes your footer Page  8 D energy losses (channels) P energy losses (channels) D energy losses (channels) P energy losses (channels) D energy losses (channels) APPLYING ADC GRAPHICAL CRITERIA ) ADC correlation w.o. TDC gates ADC correlation with TDC gates ADC CORRELATION GRAPHICAL CRITERIA

9. Here comes your footer Page  9 Time difference spectra obtained on polyethylene (a) and carbon (b) targets. CH2 DATA CARBON DATA Gauss+const fit Getting normalization coefficient fitting the time difference spectra CH2C K = const CH2 /const C

10. Here comes your footer Page  10 CH 2 -C time difference spectra subtraction Time difference distribution for dp-elastic events obtained from CH 2 -C CH 2 C TDC (channels ) Result of CH 2 -С subtraction N events

11. Here comes your footer Page  11 Event yield of dp-elastic scattering T d =880 MeV d-angle (deg. c.m.s) event yield Event yield=N dp-elastic /N pp-quasielastic T d =880MeV

12. Here comes your footer Page  12 PRELIMINARY Cross section of dp-elastic scattering T d =880MeV (mb/sr)

13. Here comes your footer Page  13 Cross section of dp-elastic scattering T d =500MeV PRELIMINARY (mb/sr)

14. Here comes your footer Page  14 Conclusions The following results has been obtained:  The procedure of the dp-elastic scattering cross-section measurements at internal target station at Nuclotron using CH 2 -C subtraction has been established.  The first results of the cross-section measurement in dp-elastic scattering at the energies of 500 and 880 MeV have been obtained. The results show the reasonable behaviour as the function of the scattering angle.  The goal for the nearest runs is to measure the cross-section of dp- elastic scattering reaction in wide deuteron energy range with the step not more than 100 MeV in the region from 500-1000 MeV.

15. Here comes your footer Page  15 Collaboration Yu.V.Gurchin a, A.Yu.Isupov a,M.Janek a,b, J.-T.Karachuk a,c, A.N.Khrenov a, V.A.Krasnov a, A.K.Kurilkin a, P.K.Kurilkin a, V.P.Ladygin a, A.N.Livanov a,S.M.Piyadin a, V.L.Rapatsky a,S.G.Reznikov a, A.A.Terekhin a, T.A.Vasiliev a  a JINR, Dubna  b P.J.Shafaric University, Koshice, Slovakia  c Advansed Research Institute for Electrical Engineering, Bucharest, Romania

16. Here comes your footer Page  16 THANK YOU! Yury Gurchin