 |
 |
 |
 |
Laboratory of Radiochemistry and Environmental Chemistry |
|
,
, |
CH-5232 Villigen PSI
Freiestr. 3, CH-3012 Bern |
Tel +41 (0)56 310
24 01
Tel +41 (0)31 631 42 42 |
|
 |
 |
 |

|
 |

Updated:
08.01.2010
|
 |

|
Tools and Instrumentation |
Heavy Elements research group (Group Leader: Robert Eichler)
|

The Cryo On-Line Detector (COLD)
|
Isotopes of transactinide elements suitable for their chemical investigation are produced on a one-atom-at-a-time scale in heavy ion induced nuclear fusion reactions. Hence, the experiments are carried out at the following accelerator facilities: the PSI Philips Cyclotron
Villigen, Switzerland (shutdown end 2007), the UNILAC
GSI Darmstadt, Germany, the 88" Cyclotron
LBNL Berkeley, USA , and the U-400
FLNR Dubna, Russia, the RIKEN Accelerator, the JAEA Tandem Accelerator, and the Lanzhou Accelerator facility. The time scale for producing one atom of the heaviest
elements reaches from minutes (261Rf) to days (283112).
|
|
The experiments employ gas jet techniques
coupled to the On-Line Gas Chromatography Apparatus
OLGA and recently, for the study of very volatile elements and compounds the
In-situ Volatilization and On-line detection IVO
system. The chemical separation has to be very efficient and selective.
The developed detection systems must have the capabilities to measure
life times and decay energies of alpha, beta and gamma-decaying and spontaneous
fissioning nuclides. These requirements are fulfilled by sophisticated
detection techniques: the PSI Tape System (PTS),
the ROtating wheel Multidetector Analyzer ROMA
and recently the Cryo-On-Line Detector (COLD).
Model experiments are carried out in order to test the efficiency and
velocity of developed chemical procedures. Therefore, the PSI Philips
cyclotron and the 252Cf fission source “Miss Piggy” at Bern
University (Miss Piggy) are used to produce short-lived
nuclides of elements, which are expected to behave homologous to the transactinides.
The experiments and the interpretation of the results are supported by
thermodynamic calculations of the stabilities, volatilities, and transport
processes as well as by Monte Carlo simulations of the gas chromatographic
process of single atoms.
|
More Pictures
The Cryo-On-Line Detector (COLD)

The Cryo On-Line Detektor (COLD)
|

The open COLD
|

The cooling finger and the detection channel
|

The open detection channel. One side is coated alternatively with gold or platinum, the other side consists of 32 Pin Diodes
|

Close up of the Pin Diodes
|

One single Pin Diode. Size compared to a match.
|
The 252-Cf fission source “Miss Piggy”
|
The 252-Cf fission source "Miss Piggy" |
|
 |
|
|
|
 |