We have recently (9/99) taken data using an electron linac Argonne Wakefield Accelerator :

We used the Argonne Wakefield Accelerator to test the properties of emission from a short (~50 picosecond) bunch of 10¹⁰ electrons at 15.2 MeV. This approximates the electrons in shower-max of a 10²¹ eV neutrino shower.

We dumped the electron beam into a bucket containing 800 pounds of silica sand. We used an S-band pyramidal horn to measure the microwave energy from 1.7 to 2.6 GHz.

We saw whopping signals, no amplifiers were needed, just attenuators. The following is a typical pulse (volts. vs. nseconds) read directly by a TDS694 oscilloscope:

We are currently writing up our results. In the meantime, visit our photo gallery:

• Peter & David with horn and target (upstream view)
• Peter adjusing cables (downstream view)
• Paul at the con
• Peter & John install the quartz window (upstream)
• David with horn
• (Only) 600 pounds of sand
• Installing quartz window
• Dick inspects our cables
• The Trigger (half-wave dipole)
• DAQ
• Peter and David place the horn
• Peter and upstream view
• Final beamline
• Mission Control
• Dick at Entrance
• Peter prepares target
• John and beamline
• Paul in control room
• Rear of horn