Systematics of angular distributions and thick-target recoil properties of deep spallation and fragmentation products of high-energy proton reactions

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5094107

Wang, C F

Angular distributions and thick-target recoil properties of deep spallation and fragmentation products of the interaction of silver, lanthanum, terbium and lutetium with multi-GeV protons have been measured. The angular distributions can be characterized by two parameters, A{sub 1} and A{sub 2}, which determine the asymmetry and the anisotropy, respectively. The thick-target results yield the values of the mean product kinetic energies and, combined with the data of angular distributions, those of the velocity of the remnant, {beta}{sub //}. The systematics of these quantities are examined both for these and other targets, ranging from silver to uranium. With the exception of light fragments (A < 30), both A{sub 1} and A{sub 2} decrease with increasing mass loss, {Delta}A, and become negative for sufficiently large {Delta}A. The corresponding laboratory angular distribution peaks shift from forward to sideward angles with increasing {Delta}A. The deviation of the very light fragments supports the idea that the formation of light fragments (A < A{sub T}/3) may involve a multi-fragment breakup process. The kinetic energies increase linearly with the fractional mass loss, {Delta}A/A{sub T} up to a value of {approx}2/3. The deviation for larger {Delta}A/A{sub T} suggests a change in mechanism from deep spallation to fragmentation for products with a mass less than {approx}A{sub T}/3. Contrary to the expectation from the two-step model, the {beta}{sub //} do not scale with {Delta}A/A{sub T}.

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• OSTI ID: 5094107
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular &amp; Chemical Physics-- Collision Phenomena
651100 -- Nuclear Physics-- Experimental Techniques-- (1980-)
653003 -- Nuclear Theory-- Nuclear Reactions &amp; Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
BARYON REACTIONS
CHARGED-PARTICLE REACTIONS
DATA
DATA ANALYSIS
DISTRIBUTION
ELEMENTS
ENERGY RANGE
EXPERIMENTAL DATA
FRAGMENTATION
GEV RANGE
HADRON REACTIONS
INFORMATION
LANTHANUM
LUTETIUM
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUMERICAL DATA
PROTON REACTIONS
RARE EARTHS
SILVER
TERBIUM
TRANSITION ELEMENTS