Review of synthesis of super heavy elements: reactions, decays and characterization. Experimental Setup of MASHA. Results of first experiments. study of evaporation residua in the reactions 40 Ar+ nat Sm and 40 Ar+ 166 Er. Our time with MASHA. Future development.

Review of superheavy elements synthesis (Z= ) in the reactions with heavy ions 48 Ca+ 233,238 U, 242,244 Pu, 243 Am, 248 Cm, 249 Bk and 249 Cf carried out in the Flerov Laboratory for Nuclear Reactions (FLNR), JINR, Dubna. The present status of the mass-spectrometer MASHA (Mass-Analyzer of Supper Heavy Atoms) designed for determination of the masses of superheavy elements. The mass-spectrometer is connected to the U- 400M cyclotron of the FLNR, JINR, Dubna. Results of the first test experiment on the mass-spectrometer MASHA aimed at the study of evaporation residua in the reactions 40 Ar+ nat Sm and 40 Ar+ 166 Er. The program of future investigations using the technique of a gas catcher is discussed. The possibilities are considered for using this mass-spectrometer for laser spectroscopy of nuclei far off-stability.

249 Cf( 48 Ca,xn) 297-x ,248 Cm( 48 Ca,xn) 293,296-x Am( 48 Ca,xn) 291-x ,244 Pu( 48 Ca,xn) 290,292-x Np( 48 Ca,xn) 285-x U( 48 Ca,xn) 286-x 112 Number of observed decay chains Element Element Element Element Element Element Element 112 8

249 Bk + 48 Ca Beam dose: 2.4x10 19 Beam dose: 2.4x Ca energy: 252 MeV 48 Ca energy: 252 MeV Target thichness: 0.31 mg/cm 2 Target thichness: 0.31 mg/cm 2 Beam current of 1-2µA Beam current of 1-2µA

Beam ( 48 Ca; MeV) Beam stop SiO 2 -Filter Ta metal 850°C Quartz column Cryo On-line Detector (4  COLD) Carrier gas He/Ar (70/30) Teflon capillary (32 pairs PIN diodes, one side gold covered) Pb Loop Temperature gradient: 35°C to – 184 °C T/C Rn 112 Quartz inlay l Window/ Target ( 242 Pu:  1.4 mg/cm 2 ) Recoil chamber

4 s 242 Pu( 48 Ca;3n) (0.5 s) → 4s Reasons a) High cross section of  4 pb (  3-times higher than via direct production with 238 U as a target) b) Residence time in collection chamber and transport capillary  2 s  9.54 MeV 4 s Ds s s

1 – Target block with hot catcher; 2 – Ion source; 3 – Mass separator; 4 – DAQ in the focal plane.

Material of the catcher – flexible graphite Operating temperature of hot catcher – о С Delivery time of nuclides to the ECR ion source ~ 2 s ECR ion source Hot catcherTargetBeam line Recoil transport

Focal plane silicon multi strip detector Configuration – well type Number of the focal strips – 192 (step – 1.25 mm) Number of the back side strips – 160 (step – 5 mm) 352 Channels

Temperature Control Vacuum Control Ion-source Control

40 Ar 5+, Beam Current = 1-2 uA, E beam = 5-6MeV/nucleon

40 Ar+ nat Sm -> Hg, E beam = 5-7 MeV/n 40 Ar+ 166 Er -> Rn, E beam = 5-7 MeV/n

Short extraction times. Extraction times of 10ms or less would be ideal. A larger scope of reactions could be studied with a shorter half-life Applicability to all fragment beams.

Faster Data transfer, 100 MB/s Less physical modules needed Digital Control Environment Synchronisation with MESHA control system Better Energy and Time resolution MESHA detector, 352 channels

The device can operate as a multi-radiation camera Portable tracking detector Frame-rate up to 5 fps Room temperature & noiseless operation Vacuum operation, no cooling Plug&Play with any PC Event by event measurement Single particle tracking mode spectroscopy Trigger and coincidence Selectivity & Sensitivity: enhanced in TimePix (ToT mode) Heavy charged particles (p, ,t, ions) Neutrons (equipped with converter) Soft X-rays MIPS (electrons, muons, , …)

Hybrid Semiconductor pixel detector Semiconductor single photon pixel hybrid detector MEDIPIX Detector chip Medipix-2 chip Bump-bonding  Planar (300, 700, 1000  m thick) silicon pixel detector (also GaAs, CdTe, or n converter) Bump-bonded to Medipix readout chip containing amplifier, discriminator and counter for each pixel.