Intermediate mass fragments from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Ar</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>40</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mo>+</mml:mo></mml:mrow><mml:mrow><mml:mn>197</mml:mn></mml:mrow></mm

Self Cite

Abstract. Inclusive cross sections of intermediate mass fragments from the reaction 84Kr-~-I97Au at ElA = 35 MeV were measured over the range 8 ~ < Olab < 70 ~ with a low detection threshold. A moving-source parameterization was used to fit the double-differential cross sections. The integrated cross section for fragment production exceeds the total reaction cross section thus indicating a large probability for multi-fragment processes. The deduced large temperature parameters can be explained by assuming emission from a rotating source. From the comparison to reactions with 12C and 4~ projectiles at E/A = 30 MeV a systematics of inclusive fragment production as a function of the projectile mass is obtained. 25.70.Lm; 25.70.Mn; 25.70.Pq to 3.6 GeV, they seem to be associated with the larger IMF multiplicities [ 11 ]. PACS:In this work the systematics of the inclusive IMF production is extended to heavier projectiles. We report cross sections for the reaction at E/A = 35 MeV which were measured with a low detection threshold over a large range of angles. The atomic number of the observed fragments extends from Z = 3 up to Z = 36. Fragments up to Z = 24 were included in the moving-source analysis of the measured double-differential cross sections. By comparing to data for the reactions 12C "q-197Au[12] and 4~ + !97Au [6], both at E/A = 30 MeV, the role of the projectile mass in this energy regime is investigated. This measurement also complements the numerous exclusive studies of the 84Kr + 197Au reaction which were conducted in order to discern the dominant mechanisms of fragment production [13][14][15][16][17].

Section: Introductionmentioning

confidence: 79%

Section: Moving-source Parametersmentioning

confidence: 96%

Section: Pacsmentioning

confidence: 99%

See 1 more Smart Citation

Inclusive fragment production in84Kr +197Au atE/A=35 MeV

Milkau

Begemann-Blaich

Eckert

et al. 1993

Self Cite

“…This indicates that equilibrium has not been reached. Studies at relativistic energies, however, have shown that the inclusive angular distributions are fairly isotropic [18], as expected for the emission from a nearly equilibrated source. A tendency towards isotropy with increasing bombarding energy was also observed by Warwick et al in their earlier work at the Bevalac [19].…”

Section: Transition From Evaporation To Total Disassemblymentioning

confidence: 88%

Fragmentation of gold projectiles: From evaporation to total disassembly

Hubele

Kreutz

Adloff³

et al. 1991

Self Cite

163

We have studied the fragmentation of Au projectiles interacting with targets of C, A1 and Cu at an incident energy of E/A = 600 MeV. The employed inverse kinematics allowed a nearly complete detection of projectile fragments with charge Z > 2. The recorded fragmentation events were sorted according to three observables, the multiplicity Mtp of light charged particles, the largest atomic number Zma x within an event, and a new observable, Zbound, representing the sum of the atomic numbers Z of all fragments with Z>__ 2. Using these observables, the impact parameter dependence of the fragmentation process was investigated. For all three targets, a maximum mean multiplicity of 3 to 4 intermediate mass fragments (IMFs) is observed. The corresponding impact parameters range from central collisions for the C target to increasingly peripheral collisions for the heavier targets. It is found that the correlation between the IMF multiplicity and Zbouna, extending from evaporation type processes (large Zbouna) to the total disassembly of the projectile (small Zbound) , is independent of the target nucleus. This universal behaviour may suggest an -at least partial -equilibration of the projectile fragment prior to its decay.

“…[18,31]). If the binary character is lost, angular momentum considerations for nuclei at normal nuclear density will be inappropriate.…”

Section: Discussionmentioning

confidence: 97%

Systematics of the power law parameter and minimum angular momenta for fragment production

Trautmann

Milkau

Lynen

et al. 1993

Self Cite

Abstract.The element yield distributions a(Z) of intermediate mass fragments from proton, helium, and heavy-ion induced reactions exhibit a universal behaviour as a function of the bombarding energy. The power law parameter ~, obtained from fits with a(Z)ocZ ~, falls monotonically with increasing projectile energy Ela b and reaches a saturation value ~-2.0 at Elab---2 GeV. It is suggested that the behaviour at low bombarding energies is caused by a dynamical hindrance of the fragment emission at low angular momentum. PACS: 25.40.Sc; 25.70.Gh; 25.70.Lm; 25.70.Mn; 25.70.Pq reactions on heavy targets. Our intention hereby is twofold. We first show that the r parameters describing inclusive cross sections exhibit a universal behaviour when plotted as a function of the total projectile energy. They decrease monotonically with increasing projectile energy until they assume a saturation value at several GeV and higher energies. We then search for possible explanations of this behaviour but limit ourselves to the lower bombarding energies. We recall experimental evidence for dynamic effect of angular momentum in fragment emission, and we show that the rise of z towards low bombarding energies may result from a dynamical hindrance of fragment emission at low angular momentum.