Velocity filter SHIP

Figure 15.7 Velocity filter SHIP. (Figure also appears in color figure section.)...

In 1981, G. Miinzenberg et al. (1981), working in Darmstadt at the velocity filter SHIP, identified the isotope 262Bh produced in the cold fusion reaction ... 

The identification of the first transuranium elements was by chemical means. In the early 1960s physical techniques were developed which allowed for detection of nuclei with lifetimes of less than one second at high sensitivity. A further improvement of the physical methods was obtained with the development of recoil separators and large area position sensitive detectors. As a prime example for such instruments, we will describe the velocity filter SHIP (Separator for Heavy-Ion reaction Products) and its detector system, which were developed at the UNILAC. The principle of separation and detection techniques used in the other laboratories is comparable. 

Velocity filter SHIP to separate transactinide fusion products from the projectile beam (reproduced with permission from G. Herrmann, An ew. Chem., Int. Ed. Engl., 1988, 27, 1422). 

At Darmstadt these elements were identified using the velocity filter SHIP, which provides an in-flight separation of the heavy-ion nuclear reaction fragments. The products were then identified by a-spectroscopic measurements of the new elements and of their decay products. The production rates are extremely low in this type of experiments. So far only 38 atoms of element 107, 3 atoms of element 108 and 3 atoms of element 109 have been observed. Attenqjts to synthesize heavier elements via the same type of reaction continue at Darmstadt, Dubna and Berkeley. 

At the velocity filter SHIP (Miinzenberg et al. 1979) at GSI in Darmstadt, a Penning trap, SHIPTRAP, has been installed (Marx et al. 2002) in which heavy-ion fusion evaporation residues can be stored for precision mass measurements and manipulated, for example, by laser spectroscopy or by chemical interactions with reactive gases. In order to explore the merits of ion-chemical investigations of heavy elements in a Penning trap, Rieth et aL (2002) have studied the reactions of Ru and Os ions with O2, thus demonstrating that ion-molecule reactions may be considered a new way to study the chemical properties of heavy elements. 

Miinzenberg, G., Faust, W., Hofmann, S., Armbraster, P., Giittner, K., Ewald, H. The velocity filter SHIP, a separator of unslowed heavy ion fusion products. Nucl. Instrum. Methods 161, 65-82 (1979)... 

These three elements were all first synthesized by the cold fusion method at GSI, Darmstadt, using a very sophisticated set of techniques. For element 107 (1981) an accelerated beam of ionized Cr atoms was made to impinge on a thin ° Bi foil the reaction recoils were separated in flight from the incoming beam and from the unwanted products of transfer reactions by a velocity filter consisting of a combination of magnetic and electric fields. This facility is known by the acronym SHIP,... 

Darmstadt GSI SHIP [46, 47] QQQEDDDDEQQQD vacuum velocity filter Recoil ID Ge detectors SHIPTRAP [48] No... 

If the forward velocity of the ship is the state variable u, a best estimate of which is given by the Kalman filter, the gain scheduling controller can be expressed as... 

The equipment most commonly used for separating fine and coarse particles is a dichotomous sampler. Again, particles are collected on filter papers and the analysis is accomplished in the same way. The typical sampler operates at high airflow velocity (about 17 L/min, depending on the design) so that sufficient Scimple ctm be collected in hours to days, compared to days or weeks for the TSP sampler. The drawback of this method is that the sampling equipment is too large to conveniently ship as an ordinary parcel and requires a trained operator to set it up properly. 

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