Facilities for Nuclear Physics Research at IUAC, New Delhi R. P. Singh IUAC, New Delhi 19-21 Feb 2014 ANPhAS-VECC

Inter University Accelerator Center (IUAC) formerly Nuclear Science Center www.iuac.res.in 19-21 Feb 2014 ANPhAS-VECC

15 MV Pelletron Tandem Electrostatic Accelerator Multi-cathode SNICS ion source SF6 insulating gas ~ 7 atm. pressure Carbon foil and Gas stripper Mass analysis and Energy analysis DC and Pulsed beams E ~ few MeV per nucleon Large number of ion-species Accelerating Column 19-21 Feb 2014 ANPhAS-VECC

Superconducting Linear Accelerator : LINAC 3 modules of 8 resonators each Solid Niobium based SC cavities (only one of this kind in our country) RF accelerating field ~ 97 MHz Operated at liquid helium temp. ~ 4 K Indigenous capability Separate High Current Injector (HCI) planned ( High Tc SC based ECR Ion source giving multiply charged ions (first of its kind in the world) Capable of doubling energy of ions from Pelletron Assembled RF cavities 19-21 Feb 2014 ANPhAS-VECC

Ion energies from IUAC accelerator systems 19-21 Feb 2014 ANPhAS-VECC

Experimental setups for nuclear physics Gamma Detector Arrays : GDA and INGA for gamma ray spectroscopy Mass Spectrometers : HIRA and HYRA: Transfer, fusion and Filter Neutron Detector Array : NAND : Fusion-fission reaction dynamics A large Scattering chamber: GPSC : Nuclear reaction studies 19-21 Feb 2014 ANPhAS-VECC

Gamma Detector Array (GDA) 12 High Purity Germanium (HPGe) dets. Each detector ~ 23% relative to 3”x3” NaI Total photo-peak efficiency ~ 0.5% @ 1MeV Peak-to-Total ~ 50% Total Ge solid angle coverage ~ 5% of 4p Conjunction with many ancillary devices: CPDA, Multiplicity filter , Plunger etc. Main work-horse : 1991 to 2007 GDA at IUAC Detector angles : 50, 90 and 144 deg. with respect to beam 19-21 Feb 2014 ANPhAS-VECC

GDA Ancillary devices Plunger for lifetime measurements in 1ps to 1ns range Phys. Rev C60 (1999)034311 Plastic phoswich type CPDA For a and p 14 element BGO multiplicity filter NIM A (2014) 19-21 Feb 2014 ANPhAS-VECC

Indian National Gamma Array (INGA) at IUAC Campaign: 2009-2011 24 Clover HPGe detectors Total photo-peak eff. ~ 5% at 1.3 MeV Peak-to-Total 40-50% Detectors angle: 32,57,90,148,123 deg Total Ge solid angle coverage ~ 25 % Indigenous electronics One of 5 large arrays in the world IUAC/TIFR/VECC/SINP/BARC/UGCDAECSR A National collaboration S. Muralithar et al; NIM A 622 (2010) 281 19-21 Feb 2014 ANPhAS-VECC

In-house Electronics developed for INGA Clover Module 14 bit ADCs Clover Power Supplies ACS Power Supplies Trigger Module LN2 Controller INGA Electronics at IUAC 19-21 Feb 2014 ANPhAS-VECC

Physics addressed: Role of high 'j' orbitals at high spins Some recent publications from GDA,INGA setups Phys. Rev C 88 (2013)024313 Phys. Rev C 88 (2013)054306 Phys. Rev Lett.. 112 (2014) 052501 Phys. Rev C 88 (2013)034303 Phys. Rev C 87 (2013)034321 Pramana 79 (2012) 403 Int. J. Mod. Phys. E20 (2011) 2133 Role of high 'j' orbitals at high spins Shape co-existence Triaxiality in nuclei Magnetic and anti-magnetic rotational bands Chirality in nuclei Octupole collectivity in nuclei Evolution of shell structure Incomplete fusion studies 19-21 Feb 2014 ANPhAS-VECC

Mass Spectrometers at IUAC 1. HIRA : Heavy Ion Reaction Analyzer 2. HyRA: Hybrid Recoil mass Analyzer 19-21 Feb 2014 ANPhAS-VECC

Heavy Ion Reaction Analyzer (HIRA) NIMA 339 ('94) 543 Acceptance: 0 - 10msr E/q accept: +-20% A/q accept: +- 5% A/A:1/350 Roation: Max. 25o MWPC + IC at Focal plane One of 4 recoil mass spectrometers of this kind in the world Excellent primary beam rejection at 0o (~ 1010 or better) Mass spectrum at focal plane position sensitive detector 19-21 Feb 2014 ANPhAS-VECC

HIRA-INGA-CPDA setup at IUAC Mass gated gamma spectra for masses 80, 82 and 83 amu Mass tagged gamma ray spectroscopy 19-21 Feb 2014 ANPhAS-VECC

Isomer decay studies at focal plane of HIRA Ideal for micro-second isomers – Flight time of ERs in HIRA Excellent, background-free region – Focal plane of HIRA Mass selected ERs stopped in catcher foil and delayed gamma transitions recorded using gamma detector at focal plane PRC 70 (2004) 014311 A. Chakrabarty et al; PRC 70 (2004) 014311 19-21 Feb 2014 ANPhAS-VECC

First RIB production in India 7Be RIB parameters: Method: p(7Li,7Be)n Inverse Kinematics Purity > 99 % Energy ~ 12 to 21 MeV (1 MeV spread) Intensity ~ 103 – 104 pps Size ~ 4 mm (FWHM) Dq,  ~ +/- 30 mrad Rotating target Gas cell J. J. Das et al. NIM B 241 (2005) 953 19-21 Feb 2014 ANPhAS-VECC

HYRA Spectrometer / Separator Dual mode Dual stage 1st stage : Gas filled opertn For A ~ 200 amu 1st and 2nd stage: Vacuum mode: For A ~ 100 Inverse kinematics Stage 1 is operational Stage 2: Q6Q7-ED-MD3-Q8Q9 16O + 194Pt at 104 MeV Beam rejection ~ 1012 Stage 1 of HYRA separator Madhavan et al; Pramana 75 (2005) 317 19-21 Feb 2014 ANPhAS-VECC

Focal plane detection system Residues Si Resistive/Strip detector Removable stopper MWPC 0.5 mm Mylar foil 19-21 Feb 2014 ANPhAS-VECC

Spin Spectrometer (TIFR) coupled to HYRA (IUAC) Angular momentum distribution in heavy nuclei formed by fusion reactions Unique setup of gas-filled separator coupled to gamma multiplicity setup Experiments of this type done only in IUAC now – Russian collaborative expt. (planned) NaI crystals covering about 85 % of 4p Also used for spin gated GDR studies G.A. Kumar et al; NIM A 611 (2009)76 EPJA Web Conference - FUSION11, Vol. 17, 14003 [EPJA Web Conference - FUSION11, Vol. 17, 16007 Nuclear Physics A, Volumes 890–891 (2012) 62-76] 19-21 Feb 2014 ANPhAS-VECC

Some recent studies using HIRA/HYRA : Fission survival of ERs by shell stabilization V. Singh et al., accepted in Phys. Rev. C (2014) G. Mohanto et al., Phys. Rev. C 88, 034606 (2013) S. Nath et al., Phys. Rev. C 81, 064601 (2010) Dissipative dynamics in fission E. Prasad et al., Phys. Rev. C 84, 064606 (2011) P. D. Shidling et al., Phys. Rev. C 74, 064603 (2006) Effect of angular momentum on ER formation G. Mohanto et al., Nucl. Phys. A 890-891, 62 (2012) S. Nath et al., Nucl. Phys. A 850, 22 (2011) Multinucleon transfer around the barrier S. Kalkal et al., Phys. Rev. C 83, 054607 (2011) Channel coupling effects in fusion S. Kalkal et al., Phys. Rev. C 81, 044610 (2010) 19-21 Feb 2014 ANPhAS-VECC

General Purpose Scattering Chamber (GPSC) and National Array of Neutron Detectors (NAND) facilities at IUAC 19-21 Feb 2014 ANPhAS-VECC

General Purpose Scattering Chamber (GPSC) A Time of Flight (TOF) set up inside 1.5 m dia GPSC Two large area 20cm x10 cm MWPC Time and position(x,y) measurements Fission fragment mass distribution studies. Pulsed beam for TOF measurement. Detect two fragments in coincidence 19-21 Feb 2014 ANPhAS-VECC

Fission fragment Angular distribution measurements using charged particle detectors inside GPSC DE-E detector telescope Thin silicon detectors or Gas ionization detector Charge particle detectors on the arm of GPSC 19-21 Feb 2014 ANPhAS-VECC

Neutron Detector Array Facility (NAND): Array of 100 detectors Liquid scintillators 5”x5” Coupled to 5” PMTs At 1.75 m from Target Chamber dia about 1 m 50 detectors installed Sugathan et al; Proc. Int. Conf. On Curr. Prob. In Nucl. Phys. (Ukraine) 19-21 Feb 2014 ANPhAS-VECC

Research Program with Neutron Detector Array Measure neutrons in coincidence with fission fragments Extract pre-scission and post-scission neutron multiplicity at high Excitation energy. Study of multiplicity distribution using large array. Two MWPC detectors Inside the chamber 19-21 Feb 2014 ANPhAS-VECC

Some recent studies using NAND/GPSC setups: Effect of shell closure on nuclear dissipation : Phys. Rev. C 86 (2012) 014609 Quasi-fission : Phys. Rev. C 81 (2010) 054608 Entrance channel effect in fission : Phys. Rev. C 80 (2009) 024603 Nuclear dissipation : Phys. Rev. C 80 (2009) 064615 19-21 Feb 2014 ANPhAS-VECC

Summary Major facilities at 15 UD Pelletron + LINAC accelerator lab IUAC, New Delhi, for nuclear physics research are: Gamma Detector Arrays : GDA and INGA setups Mass spectrometers: HIRA and HYRA (hybrid) Array of neutron detectors : NAND General purpose scattering chamber: GPSC These facilities have been used heavily by Indian and foreign nuclear physicists to address vital problems of current interest. 19-21 Feb 2014 ANPhAS-VECC

THANKS for your Attention Qutub Minar, New Delhi 19-21 Feb 2014 ANPhAS-VECC

Power Supplies & Controllers designed/developed at IUAC (Import Substitution, Technology transfer, New Features, Easy Maintenance, ..) Quadrupole Power Supplies (300 A and 100 A) with excellent current stability Input Gate Output Register Clover HPGe bias supplies BGO bias supplies Power Supply controllers 19-21 Feb 2014 ANPhAS-VECC

Superconducting Quadrupole Doublet To increase angular acceptance of HYRA by a factor of ~ 2.5 Increase in transmission efficiency of HYRA, as a result Designed at IUAC with help from NSCL, MSU (USA) 19-21 Feb 2014 ANPhAS-VECC

19-21 Feb 2014 ANPhAS-VECC