The first gamma-ray burst instrumentation

In the mid-sixties the Universe was thought to be quite bland, so the first instruments that detected gamma-ray bursts (GRBs) were intended for a very different application. Through fortuitous similarity with the techniques needed to detect nuclear explosions, the Vela satellites had the ability to recognize that a GRB is occurring, provide enhanced telemetry for the burst, and locate it (Chapter 1; Klebesadel et al. 1973). These characteristics have been necessary for virtually all subsequent GRB instrumentation. Instrumentation for all other high-energy astrophysics applications know what direction to look and when. The randomness of GRBs in space and time requires specialized adaptations of the standard gamma-ray detectors used on the ground (scintillators, proportional counters, solid state detectors, charge-coupled devices (CCDs)). In the following sections, we will discuss the principles and strategies used in GRB instrumentation in four areas that dominate a design: spectral techniques, temporal techniques, determining a direction to the burst, and networks of multiple-wavelength sensors.

Spectral techniques

The early workhorses of GRB instrumentation were gamma-ray scintillators such as NaI and CsI used in, for example, the Konus experiments (Mazets et al. 1981), the Pioneer Venus Orbiter (PVO; Klebesadel et al. 1980), the International Sun–Earth Explorer (ISEE-3; Anderson et al. 1978), the French-Soviet Venera satellites (Barat et al. 1981) and the Solar Maximum Mission (SMM; Forest et al. 1980). Hurley (1984) has a detailed review of the early instrumentation. Gamma rays interact within a crystal, producing an optical signal that is processed by a photomultiplier.