Enrique Bronchalo

An electronic device that suits space research requirements for ion detection

An electronics system for low-energy cosmic ion detection has been designed and built. This instrument was designed to he shipped onboard a satellite with a mission to detect solar energetic particles (SEP) and to study the anomalous component of cosmic rays. The electronics of the instrument were verified by four functional tests. In the first of these tests, its response to well-known electronic pulses, analogous to those produced in the detectors, was checked. During the second test, the coincidence-anticoincidence performances have been verified. The third test consisted of the calibration of each detector and its corresponding electronics chain with alpha particles from a /sup 241/Am source. All these preliminary tests were carried out in an Alcala University laboratory. The final test was done with nuclear reaction fragments at the VICKSI (Van de Graaff Isochron Cyctotron Kombination fur Schwere Ionen) heavy ion accelerator facility of the Hahn Meitner Institute in Berlin. The trails proved to be successful, with satisfactory results when compared with those achieved by standard nuclear instrumentation.

Detector system for low-energy cosmic ions study

Abstract A low-energy cosmic ion detector system composed of a telescope and its amplification electronics has been designed and constructed. The detector system is able to detect ions from hydrogen to iron in the energy range of 1–50 MeV/nucleon. The amplification electronics has been designed using space components so that its weight, dimensions and power consumption would be small enough to allow the telescope to be used for cosmic ion detection in space aboard a satellite. The system was calibrated in a heavy ion accelerator, and the results show good charge and mass discrimination for the registered ions as well as a good response from the amplification electronics.

Charge systematic errors associated with identification methods for heavy-ion ΔE–E telescopes

Abstract The contribution of identification methods to charge systematic errors for heavy-ion Δ E – E multidetector telescopes is studied. In this context, a new identification method is presented in two versions: the first uses one Δ E value and second uses all Δ E data for each event. A Monte Carlo simulation of the response of a solid-state telescope to an isotropic flux of heavy ions is used to test the systematic errors induced by this method and by the Seamster and range methods.

Parametrization of charge and mass resolution for ΔE − E telescopes

Abstract A simple parametrization of energy straggling of 2–200 MeV/nucleon heavy ions traversing thick silicon detectors, based on the Tschalar-Payne theory, is presented. With this parametrization, analytical expressions for the charge and mass resolution of energetic ions detected on ΔE − E telescopes can be obtained. Several consequences that can be extracted from these expressions are analysed, especially, in what concerns the thickness selection for multi-detector telescopes. The validity of those analytical formulae are tested with experimental resolutions obtained from calibration data of three different cosmic-ray telescopes.

Low energy ion identification method using a silicon semiconductor detector telescope

A method for discriminating cosmic ions that can be applied at low energies using ΔE-E is presented. The method is tested with a simple detector telescope, consisting of surface barrier silicon detectors. The results obtained irradiating the detector with 32S ions at 795 MeV are presented and then compared with those obtained by applying the Seamster et al. algorithm.

Evidence of Magnetic Flux Ropes in the Solar Wind From Sigmoidal and non-Sigmoidal Active Regions

We have examined WIND magnetic field and plasma data during the first half of 1998 in order to find encounters of this spacecraft with magnetic clouds. From the events obtained through this search, we have selected four of them taking into account their solar origin. The four magnetic clouds are related to halo or partial halo CMEs, but the morphology of the active region before the eruption is sigmoidal for three of them and non-sigmoidal for the other one. We have analyzed these events in the solar wind by fitting the experimental data to a non-force-free flux-rope model. We conclude that both kinds of active regions develop in the solar wind an ejection with a flux-rope topology.

Low-cost programmable pulse generator for particle telescope calibration☆

Abstract In this paper we present a new calibration system for particle telescopes including multipulse generator and digital controller. The calibration system generates synchronized pulses of variable height for every detector channel on the telescope. The control system is based on a commercial microcontroller linked to a personal computer through an RS-232 bidirectional line. The aim of the device is to perform laboratory calibration of multi-detector telescopes prior to calibration at accelerator. This task includes evaluation of linearity and resolution of each detector channel, as well as coincidence logic. The heights of the pulses sent to the detectors are obtained by Monte Carlo simulation of telescope response to a particle flux of any desired geometry and composition.

Control system for a low energy particle detector

In this paper we describe the hardware and software employed to control a solid state telescope particle detector, part of the Russian PHOTON satellite, which is planned to be launched in 1999. The development of this kind of instruments has several restrictions due to the special working environment conditions. The solution proposed is based on two hardware modules (analog and digital) and on a control software. There are also shown some of the results obtained on a calibration carried out in the GANIL particle accelerator.