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This experiment is to obtain the excitation functions of the 13C (α, α)17O elastic scattering at the initial beam energy 13C from 1.7Mev/A till energies close to zero by using the Thick Target Inverse Kinematics method (TTIK). The experiment will be made in Astana by using a new heavy ion accelerator DC-60 which provides beams with the energy 1.75 MeV/nucleon. The experimental data will be analyzed using R-matrix method to determine excitation energies, quantum characteristics and widths of the 17O levels near the threshold of the decay into 13C and α-particle. [2]

Experimental Setup

Study of the resonance α+13C interaction at low energies: Optimization of parameters of the beam shape

D. Beznosko(1), А. Batyrkhanov(1), Т. Beremkulov(1), А. Duspayev(1), V. Goldberg (3), A. Iakovlev (2), N. Mynbayev (2), D. Nauruzbayev (2), A. Nurmukhanbetova(2), G. Rogachev(3), М. Yessenov(1)*

(1)Cosmic Rays and Particles group, Nazarbayev University, Astana, KZ (2) National Laboratory Astana, Astana, KZ (3)Texas A&M University, Cyclotron Institute, USA

* presenter

Bibliography[1] HAMAMATSU PHOTONICS K.K., Electron Tube Division, 314-5,

Shimokanzo, Iwata City, Shizuoka Pref., 438-0193, Japan, http://www.hamamatsu.com/

[2] Mynbayev, N. A., Nurmukhanbetova, A. K., Gol’dberg, V. Z., Golovkov, M. S., Rogachev, ... & Tribble, R. E. (2014). Study of the excitation function for the 13C+ 4He elastic scattering with the thick-target inverse kinematics method. Journal of Experimental and Theoretical Physics,119(4), 663-667.

[3] D. Beznosko, G. Blazey, A. Dyshkant, V. Rykalin, J. Schellpffer, V. Zutshi, "Modular Design for Narrow Scintillating Cells with MRS Photodiodes in Strong Magnetic Field for ILC Detector", NIM A 564:178-184,2006.

[4] Mesytec GmbH & Co. KG, Wernher-von-Braun-Str. 1, 85640 PutzbrunnGermany. http://mesytec.com

An Eljen 201 plastic scintillator piece 30 mm x 30 mm x 5 mm will be used. I. With alpha source,

the optical cross-talk between PTM channels via scintillator itself will be measured.

II. The scintillator piece will be grooved 2-2mm deep, grooves will be filled with TiO2 , and cross talk will be measured again

Abstract

For measurement accuracy and errors reduction the profiling of the beam within the experimental camera is needed. For that we proposed to use 64-channel (H 7546B) Hamamatsu [1] PMT with plastic scintillator in front of it, placed within the camera after the beam window.

Plastic scintillator R&D

DAQCurrent results

An accelerated 13C beam enters scattering chamber filled with helium-4 (99.9%) passing through a thin window (with 2.5-µm havar film). Helium-4 plays role of target and degrader for a entering beam. The pressure in the chamber is chosen such that the beam stopped in helium at a distance of 50 mm from the back wall of the chamber, where detectors placed. Detection is made by 15 square p-i-n Si detectors with an area of 100 mm2 and a thickness about 350 µm. The energy resolution of detectors was about 30 keV. [2]. Beam profiling will be done both in vacuum and at working pressure.

Shaper Mesytec STM 16+ differential [4]• 16 channel NIM module, low power

design • 2 shaping times: 0.5 us/1 us or

2us/5us• Low noise: < 7uV• Digital delay of 450 ns for timing

stop • ECL timing output• Trigger output • Multiplicity trigger • Remote control of discriminator

thresholds and gains

Mesytec MADC-32 [4]

• 800 ns, 1.6 us, 6.4us conversion time for 32 channels with 2k, 4k, 8k resolution.

• Zero suppression with individual thresholds

• Two register adjustable gate generators are built in

Calibration run:• PMT and its holder• Shaper• ADC• PC

PMT with holder

The main part of the experiment is an elastic scattering interaction cross-section +13C . Excitation function of elastic scattering reaction at 0 degree relative to beam direction in center of mass system is shown in Figure below. In this work, at first time we succeeded to observe resonances in the +13C interaction at the lowest energies at 0 degree where resonances dominate over the potential scattering. As a result we have found new structures in the region in question. Our experimental data will be analyzed further by R-matrix method to understand these peaks [2]

Layout of the experiment using TTIK method

Motivation 2 run types:I. Calibration run: PMT is placed at

different distance from beam entering window to obtain the picture of beam development

II. Science run: Without PMT

• Input range, register selectable 4 V, 8 V, 10 V

Analysis• NSCL Data Acquisition System software

Grooved plastic scintillator [3]

Beamline testing of measuring beam profile setup using both smooth and grooved plastic scintillator is planned for August 2015

Excitation function of elastic scattering reaction at 0 degreePMT holder and connector rig