  The paper describes a new E-Delta-E detection module which includes a
position-sensitive double-sided strip detector (DSSD) and a low-pressure
pentane-filled Delta-E chamber for detection of Evaporation Residues (ER) in
complete fusion nuclear reactions. The goal is to synthesize superheavy
isotopes at the new DC-280 (Dubna Cyclotron) cyclotron of the Joint Institute
for Nuclear Research (JINR). With the 48Ca ion beam intensity of about 5-7 pmcA
(particle micro ampere) and the Delta-E counter count rate of approximately
1.0E+4 sec-1, we observe a decrease in the overall registration efficiency of
the gas Delta-E counter. The paper proposes a solution to this problem:
introduction of an additional negatively biased electrode, which results in the
stabilization of the Delta-E detector operation.
