The scintillation characteristics of pure and Tl-doped CsI were investigated. The scintillation light was detected with photomultipliers and silicon photodiodes. The influence of the Tl concentration on the light yield and on the decay times was studied upon excitation with gamma -rays and alpha -particles. The origin of the different emission components is discussed. >

Scintillation characteristics of pure and Tl-doped CsI crystals

This article describes the crystal selection and quality control utilized to develop and calibrate a high-resolution array of CsI(Tl) scintillator crystals for the detection of energetic charged particles. Alpha sources are used to test the light output variation due to thallium doping gradients. Selection of crystals with better than 1% non-uniformity in light output is accomplished using this method. Tests with a 240 MeV alpha beam reveal that local light output variations within each of the tested CsI(Tl) crystals limit the resolution to about 0.5%. Charge and mass dependences in the energy}light output relationship are determined by calibrating with energetic projectile fragmentation beams. ( 2001 Elsevier Science B.V. All rights reserved.

https://www.nscl.msu.edu/~tsang/csi3_paper.pdf

Energy resolution and energy–light response of CsI(Tl) scintillators for charged particle detection

A facility for measurements of neutron-induced double-differential light-ion production cross-sections, for application within, e.g., fast neutron cancer therapy, is described. The central detectio ...

A facility for measurements of nuclear cross sections for fast neutron cancer therapy

The response function of 2-cm-thick CsI(Tl) scintillators with photodiode readouts were studied by directly exposing the detectors to beams of heavy ions (2≤Z≤36) with energy up to 25 MeV/u. The dependence of the light output on the energy (E) as well as on the atomic number and the mass of the ion is analyzed and discussed, and a parameterization of the light output as a function of Z and E is proposed.

https://wwwusers.ts.infn.it/~milazzo/pubblicazioni/P04.pdf

Calibration of the response function of CsI(Tl) scintillators to intermediate-energy heavy ions

The momentum and density dependence of the mean field in nuclear matter has been studied with phenomenological effective interactions with particular emphasis on the influence of the functional form of the interaction in determining the high density and high momentum behaviour of the mean field. Emphasis is also given to choosing the effective interaction in a form simple enough to permit analytical calculations of various properties of nuclear matter with a minimum number of adjustable parameters. These simple effective interactions are found to have a zero-range density-dependent part similar to Skyrme interactions and a long-range density-independent part of conventional form, such as Yukawa, Gaussian and exponential. It is observed that the high density and the high momentum behaviour of the mean field in nuclear matter is essentially governed by the nature of the density dependence and the precise functional form of the long-range part of the exchange component of the effective interaction. The parameters of these interactions can be constrained to obtain a mean field in nuclear matter which is independent of the functional form of the exchange interaction in the range of momentum k = 0- and up to a density four times the standard nuclear matter density. However, beyond this range the functional form of the exchange interaction becomes important in determining the momentum and density dependence of the mean field in nuclear matter.

https://iopscience.iop.org/article/10.1088/0954-3899/24/11/009/pdf

Momentum and density dependence of the mean field in nuclear matter

The luminescent response of a CsI(Tl) crystal has been determined for light and heavy ions (Z ≤ 14) with energies up to 800 MeV. These fragments were produced in a 28Si + 28Si reaction at beam energies between 22 and 35 MeV/nucleon. A nonlinear response was observed over the entire energy range. A parametrization of the light output, L(Z, E), is given. The scintillator response was found to be proportional to E1.3 for Z ⩾ 3. The scintillation efficiency has been determined. The overall features can be described within an existing model, if the effect of secondary electrons is taken into account.

The response function of a CsI(Tl) scintillator with photodiode readout to light and heavy ions in the intermediate energy range

Detailed angular distributions of protons and \ensuremath{\alpha} particles detected in coincidence with evaporation residues have been measured for the reaction $^{28}\mathrm{Si}$${+}^{28}$Si at 12.4, 19.7, and 30.0 MeV/nucleon. We have separated these angular distributions into pre-equilibrium and evaporation components. The invariant velocity distributions of pre-equilibrium protons are typical for nucleons emitted by jetting processes, while the distributions of pre-equilibrium \ensuremath{\alpha} particles are typical for particles produced in breakup reactions. The charge and energy balance in the reaction allows us to reconstruct the average properties of the compound nucleus and to deduce the effects of the reaction dynamics. At 12.4 MeV/nucleon only a few pre-equilibrium light particles are emitted prior to fusion, whereas at 19.7 and 30.0 MeV/nucleon hot nuclei are formed in breakup-fusion reactions. All of our results can be fully explained assuming that compound nuclei do not produce evaporation residues if their excitation energy is above 4.3 MeV/nucleon.

Fusion of si-28 nuclei at 12.4, 19.7, and 30.0 mev nucleon

The fusion and subsequent decay of the system 40Ca+48Ti has been studied at 25.0 and 33.9 MeV per nucleon bombarding energies. Heavy residues were detected in coincidence with light particles, and evaporation residue cross sections have been extracted. Light particle distributions are well described by a simple kinematical model, and from this the average excitation energies of the system were determined.

Evaporation residue cross sections for 40 Ca + 48 Ti at 25.0 and 33.9 MeV per nucleon

Limiting excitation-energy in the reaction si+si

Inclusive velocity spectra of heavy ions produced in the [sup 28]Si+[sup 28]Si reaction at 22, 26, 30, and 35 MeV per nucleon were measured and decomposed into peripheral and central components using an analytical moving-source parameterization. The persistence of incomplete fusion followed by evaporation has been observed over the entire bombarding energy range. Ratios of parallel and perpendicular momentum widths for fusion events show a growth of preequilibrium emission with increasing beam energy. The evaporation-residue data are consistent with a limit of 6 MeV per nucleon excitation energy beyond which conventional evaporation becomes significantly less probable. This limiting value is compatible with what one can expect from the balance between nuclear relaxation times and times for particle evaporation.

P.F. Box

Papers

The response function of a CsI(Tl) scintillator with photodiode readout to light and heavy ions in the intermediate energy range

Fusion of si-28 nuclei at 12.4, 19.7, and 30.0 mev nucleon

Evaporation residue cross sections for 40 Ca + 48 Ti at 25.0 and 33.9 MeV per nucleon

Limiting excitation-energy in the reaction si+si

Inclusive systematics for si-28+si-28 reactions between 20 and 35 mev per nucleon