Juan Andrés Agapito Serrano

Instrumentation Amplifiers and Voltage Controlled Current Sources for LHC cryogenic Instrumentation

Instrumentation amplifiers and voltage controlled current sources have been designed by using single operational amplifiers (OPA124, TLE2071 and OPA627). Their performance has been evaluated in the laboratory and under neutron radiation. On line measurements of the offset voltages, offset currents, closed loop gain, CMRR and bias currents were performed on the amplifiers. The current sources were set to a constant value and the current was monitored on-line. The radiation tolerance of commercial voltage references has also been investigated. The radiation was performed out in ITN (Portugal) research nuclear reactor. In comparison to previous experimental campaigns the gamma radiation has been reduced by a factor 15 for a given neutron dose. This is achieved thanks to a recently constructed facility for neutron beam extraction

Radiation tests on commercial instrumentation amplifiers, analog switches & DAC's

A study of several commercial instrumentation amplifiers (INA110, INA111, INA114, INA116, INA118 & INA121) under neutron and vestigial gamma radiation was done. Some parameters (Gain, input offset voltage, input bias currents) were measured on-line and bandwidth, and slew rate were determined before and after radiation. The results of the testing of some voltage references REF102 and ADR290GR and the DG412 analog switch are shown. Finally, different digital-to-analog converters were tested under radiation.

Preliminary test for radiation tolerant electronic components for the LHC cryogenic system.

The LHC accelerator will use about 1600 main superconducting magnets operating below 2K. The magnets temperature is a control parameter and its target accuracy imposes very severe constraints on both the sensing element and its signal conditioner. They will both be installed inside the tunnel, thus exposed to a relatively high neutron fluence and gamma dose. It is then crucial to understand the effects of radiation on the performance of the electronic components that will be selected for the signal conditioner. This paper presents data concerning the radiation effects on typical active and passive discrete electronic components. This is the first step toward building a radiation tolerant signal conditioner.

Rad-Tol Pt-100 Isolation Amplifiers for the LHC Cryogenic System

The cryogenic system of the LHC will use Pt-100 sensors to measure temperatures between 40-300K and isolation devices will be used. The selected commercial components must be rad-tolerant since a total radiation dose of 5E12 n/cm2 &100 Gy is expected during ten years of the LHC lifetime. Neutron tests in this family of devices were performed and the results are shown in this paper.