A1900 Hardware and Detectors

This page provides a brief introduction to what hardware and detectors are located where in the A1900. A more detailed list providing the most up-to-date description of the standard A1900 detector and hardware configuration can be found at the A1900 Technical Information page. A list of the options currently installed in the standard A1900 configuration is also posted on the web.

All detectors, viewers, targets, slits, and wedge degraders used with the A1900 can be remotely inserted into the beam and removed. The items which are inserted at the time a Barney saveset is made are documented in the saveset.

The vacuum chamber at the A1900 target position contains 4 ladder drives (named Z013TL, Z014TL, Z015TL, and Z016TL) each with up to 8 positions for holding things like targets, thin stripping foils, viewers, and apertures. A faraday cup for measuring beam current is located on Z014TL. Z015TL is at the A1900 object position; Z013TL and Z014TL are upstream of the object position, and Z016TL is downstream. A list of the commonly used targets and apertures is availible in the target inventory.

The vacuum chamber at Image 2 (I2) contains a number of devices. A ladder drive holds up to three wedges and a viewer. (A list of the commonly used wedges and targets is availible in the wedge inventory.) There are two drives for remotely inserting slits which are manually adjustable only when the system is not under vacuum. There is a pair of parallel plane avalanche counter (PPAC) detectors for tracking the horizontal and vertical position of particles passing through them. There is also a thin scintillator detector which is used to provide timing start or stop signals for particles passing through them.

The vacuum chamber at Image 3 (I3) contains a remotely-adjustable set of horizontal and vertical slits. It also has a ladder drive which holds a viewer and one degrader.

The vacuum chamber at the focal plane (FP) contains most of the detectors typically used in the A1900. A pair of PPAC detectors is used in obtaining proper positioning for particles at the focal plane. A thin silicon PIN detector measures the energy loss of the particles passing through it. A thick scintillator is used to measure the energy and arrival time of particles that it stops.

The vacuum chamber at the extended focal plane (XF) has drives for inserting viewers in front of each of the three beam line branches that start just downstream of the A1900. Each beam line has its own remotely-adjustable horizontal slits. A thin scintillator (for measuring timing) and thin silicon PIN detectors (for measuring energy loss) are available in front of some of the beam lines.