Isotopic Thin Films Preparation Laboratory for Nuclear Physics

Isotopic Targets
Engage in the Romanian Research Infrastructure System
Contact persons: Nicoleta-Mihaela FLOREA - nicoleta.florea@nipne.ro, Andreea RADU - andreea.mitu@nipne.ro

The laboratory was developed to support the nuclear physics experiments performed mainly at the IFIN-HH 9 MV Tandem Accelerator or at other international research facilities in the frame of scientific collaborations (CERN, IN2P3, TUM, IKP, JINR, etc). The laboratory provides thin films of various thicknesses made from both naturally occurring materials and stable enriched isotopes. Such thin films (called “targets”) are dedicated for different types of nuclear structure experiments: nuclear structure and lifetimes measurements of excited nuclear states using γ-ray spectroscopy techniques (Doppler shift attenuation, plunger, and fast-timing), nuclear structure studies using the activation technique, cross-section measurements of interest for nuclear astrophysical processes,etc. To assure good target quality the laboratory includes state-of-the-art equipments used for thin-film fabrication technology and consist of Physical Vapor Deposition (PVD) and mechanical rolling techniques.

High Vacuum Deposition Systems
High Vacuum Deposition Systems

The system is used for creating thin films by thermal resistance, electron based systems and by sputtering methods.

Deposition Chamber
(a.) rotating substrate holder; (b.) thermal evaporation; (c.) electron-gun evaporation system; (d.) sputtering deposition system; (e.) quartz crystal monitor; (f.) shutter; (g.) electron-beam system produced by Mantis Deposition.
Inside View of the Deposition Chamber
  • The system features a stainless steel cylindrical chamber (45 cm diameter and 53 cm high), placed on the top lid together with the rotary heater and the substrate. The heater of the system is specially configured to reach a maximum temperature of 700 °C. The chamber includes a frontal 4-inch viewport that is placed in an ISO-KF DN100 flange. The chamber has a motorized hoist to raise and lower the top lid and the vacuum chamber.
  • The setup is equipped with a high-vacuum system capable of pumping down the chamber to a pressure level below 3.5E-5 Torr.
  • The system has also one resistive evaporation kit with a 3.6 kW power supply (6 V and 600 A) for evaporation of materials with melting points not higher than 1800 °C.
  • For making targets of high melting point materials (up to 3800 °C) and dielectrics, the system is equipped with two electron based systems. An electron-gun and a 4-pocket 9 x 2 cc volume rotary water-cooled copper crucible which allows sequential evaporation of up to 4 materials. The electron-gun has a 270 ° deflection angle, 5 kV acceleration voltage and 600 mA maximum current and is equipped with a XY sweep controller. Recently, a second e-beam system produced by Mantis Deposition Systems was integrated in the vacuum deposition chamber of TE18-High Vacuum Deposition System. The system is equipped with a QUAD-EV-C source with a power supply of 500 W that can be used to heat the target material to temperatures up to 3000 °C. The target rod/crucible is located close to the W filament. When the current through the filament is sufficient, the electron emission temperature is reached and a stream of electrons is drawn from the filament towards the rod/crucible. Their impact on the rod increases the temperature, which leads to evaporation of the rod or the material placed in the crucible. A Quad- EV-C source is used to ensure optimum control of the evaporation rate at low fluxes. This system is equipped with four pockets of 390 mm3; each one uses independent filaments, flux and high voltage channels. It can be used for multilayer deposition by independent monitoring of the deposition rate. The main advantage of this system is that all parameters can be monitored and controlled by means of software applications.
  • The equipment contains a 2.5 cm diameter water-cooled magnetron-sputtering source, mounted in the base plate of the chamber. The magnetron source is powered with a 300 W RF power supply and a 13.54 MHz plasma generator with manual matching network.
  • The system has an Inficon SQM160 Thin Film Deposition Monitor for monitoring the thickness of the deposited material and the rate of deposition.
  • Quorum Technologies E6700 Bench Top Evaporator
    Quorum Technologies E6700 Bench Top Evaporator

    This system is equipped with power supplies for both carbon and metal evaporation. It includes sputtering, glow discharge, low angle shadowing, and film thickness monitoring. The work chamber with a diameter of 30 cm can be evacuated to less than 10-5 mbar. In standard operation we apply up to 10 V at 200 A for carbon coating and 20 V at 100 A for metal evaporation.

    Rolling is extremely efficient for self-supported metallic foil production using small amounts of starting material. It allows preparation of metallic foils with areal densities ranging from several hundreds of μg/cm2 to hundreds of mg/cm2.

    DRM 100 Rolling Unit
    Durston Type DRM 100 Rolling Mill

    Electrically controlled rolling mill with variable speed. The rolls have a size of 100 x 50 mm and are made of specially selected roll steel, heat-treated on the main working surface.

    Durston FSM 160 VCC Power Rolling Mill
    Durston FSM 160 VCC Power Rolling Mill

    It is a powerful, double sided, electrically controlled and with touch screen display rolling mill with variable speed (5-20 rpm). It is a 3 phase voltage, floor standing system with a 4kW electric motor power equipped with 160 x 86 mm rolls, made of specially selected roll steel, heat-treated on the main working surface. It has a maximum roll gap opening of 25 mm and the lubrications to roll bearings is automated.

    For producing self- supported pellets, which can be further used in experiments as thick targets the pressing method is also used.

    Atlas™ Automatic 25Ton (25T) Hydraulic Presses, Specac
    Atlas™ Automatic 25Ton (25T) Hydraulic Presses, Specac

    equipped with 40 mm, 32 mm, 20 mm, 13 mm, 20 mm and 5 mm evacuable pellet dies.All the parts of the die are manufactured from hardened stainless steel for optimum quality and durability, and highly polished surfaces for contact with the sample. The applied pressure and release are well controlled. The LCD display show press status and load conditions giving a digital display of the load applied.

    Mettler Toledo XP microanalytical balance, XP56/M
    Mettler Toledo XP microanalytical balance, XP56/M

    The Mettler Toledo XP microanalytical balance offers a weighing capacity of 52 g with 0.001 mg readability.

    Nabertherm Tube Furnance (1300°C)
    Nabertherm Tube Furnance (1300°C)

    Nabertherm Tube Furnance (1300°C) is equipped with a gas supply systems for protective gas or vacuum operation.

    Micro Centrifuges, FC5515R, Ohaus
    Micro Centrifuges, FC5515R, Ohaus
  • Speed Range: 200 rpm – 15,200 rpm
  • Maximum Relative Centrifuge Force (x g): 21,953 g
  • Maximum Capacity (Rotor): 44 x 1.5 / 2.0ml;12 x 5 ml
  • Refrigeration Range: -4 °F – 104 °F (-20 °C – 40 °C).
  • Isotopic targets for experiments performed at the Tandem 9MV

    PAC 2019 (January-December)

    Nr. Nuclear physics experiments Isotropic targets
    1 C. Petrone et al., IFIN-HH, Magurele, Romania Shape coexistence in neutron deficient 70Se 58Ni (1 mg/cm2)
    2 M. Boromiza et al., IFIN-HH, Magurele, Romania Proton inelastic scattering cross sections on 58Ni 58Ni (0.3 mg/cm2)
    3 R.E. Mihai et al. IFIN-HH, Magurele, Romania Lifetime measurement of the first 3/2+ state in 49Cr through the RDDS plunger method 46Ti (0.4 mg/cm2) / Au (2mg/cm2)
    4 B. Fornal et al., IFJ PAN, Krakow, Poland Addendum to the proposal “Searching for shape coexistence in 64Ni” 65Cu (5 mg/cm2)
    5 I. Gheorghe et al., IFIN-HH, Magurele, Romania Radiative proton capture cross section measurements on Zr isotopes natZr
    6 T.J. Mertzimekis et al., University of Athens, Greece Investigate deformations and the onset of octupole correlations in 140Ba: a continuation study natBa (2 mg/cm2) / Au (5 mg/cm2)
    7 T. Beck et al., Institute for Nuclear Physics (IKP), TU Darmstadt, Germany Shape of the intruder band of 96Zr - Measurement of τ(4+) and τ(2+3 ) using the Doppler-Shift Attenuation Method 94Zr (8 mg/cm2)
    8 S. Bottoni, S. Leoni et al., University of Milano and Sez. INFN Milano Understanding collectivity and shape transitions in Zn isotopes across N=40 by measuring γ-ray decays and lifetimes of low-lying off-yrast states in 72Zn42” 70Zn (4 mg/cm2)
    9 M. Sferrazza et al., Université libre de Bruxelles (ULB), Belgium Detailed Spectroscopy of 62Ni: searching for the onset of shape coexistence in the neutron rich side of the Ni chain 63Cu (5 mg/cm2)
    10 A.M. Bruce et al., University of Brighton, Brighton, UK. Progress report on – Characterisation of the non-yrast levels in 102Mo 100Mo (0.8 and 1 mg/cm2)
    11 R. Lica, M.J.G. Borge et al, IFIN-HH, Magurele, Romania and Instituto de Estructura de la Materia, CSIC, Madrid, Spain Lifetime measurement of the 0+2,3 states in 32Si near the N=20 ”Island of Inversion” 30Si (0.2 mg/cm2) / Ti (3 mg/cm2) 30Si (0.2 mg/cm2) / Ta (13 mg/cm2) 30Si (117 mg/m2)
    12 A.B. Garnsworthy et al., TRIUMF, Vancouver, Canada Shape-coexistence and triaxiality in 74Ge 72,73Ge (1.6 mg/cm2) / Au (8 mg/cm2) 74As (500 mg/cm2)
    13 A. Görgen et al., University of Oslo, Norway Spectroscopy and lifetime measurements in 126Sn following two-neutron transfer reactions 124Sn (0.5 mg/cm2) / Au (3 mg/cm2)
    14 P.R. John et al., GSI Helmholtzzentrum fur Schwerionenforschung and Institute for Nuclear Physics (IKP), TU Darmstadt, Germany Quadrupole transition strength of the first excited state of 200Pt: towards the N = 126 shell gap 198Pt (1 mg/cm2)
    15 Th. Kröll et al., Institute for Nuclear Physics (IKP), TU Darmstadt, Germany Competition between shell model and α-cluster states in 212Po: lifetime of the first 4+ state 208Pb (10 mg/cm2)
    16 I. Harca et al., IFIN-HH, Magurele, Romania The unexpected asymmetric fission in Hg nuclei 182,184 W (0.2 mg/cm2) / C (0,03 mg/cm2)

    Isotopic targets for international laboratories (IFJ PAN, Krakow, Poland; JINR, Dubna, Russia; JYFL Accelerator Laboratory, Finland)

    No. Nuclear physics experiments Isotopic targets
    1 S. Leoni et al., University of Milano and Sez. INFN Milano, Italy Study of M4 stretched configuration decay in 13C, Proposal for CCB IFJ PAN experiments 13C (200 mg/cm2) / 13C (0.5 mg/cm2)
    2 S. Leoni et al., University of Milano and Sez. INFN Milano, Italy Study of M4 stretched configurations decay in 14N, Proposal for CCB IFJ PAN experiments Li14NH2 (200 mg/cm2)
    3 Emanuele Vardaci et al., University of Jyvaskyla, Finland Fission modes of 174Hg via the reaction 78Kr + 96Ru at low excitation energy, Proposal for JYFL Accelerator Laboratory, Finland 116,117,119Sn (0.25 mg/cm2) / C (0.03 mg/cm2)
    4 Proposal for JINR, Dubna, Russia experiments 142,143Nd2O3 (0.25 mg/cm2) / C (0.03 mg/cm2) 144,154Sm2O3 (0.25 mg/cm2) / C (0.03 mg/cm2)