Improvements HRRL Positron Runs July 2012

1. Make T2 holder without vertical 45 deg angle.

2. Improve TDC inputs, and DAQ system (use veto on the CFD).

3. Put better (more sensitive, thicker) scintillator at the exit of 90 deg, so I can measure the numbers of positrons.

4. Take more data on 3 MeV and 4 MeV positrons.

5. Measure the energy spread of positrons by changing slit width for different energies (1, 2, 3, 4, MeV).

6. It seems we don't need the ion pump at 90 deg beamline, it can be removed next time.

7.

Run Plan

Tune electron beam

Tune Energy

1. Put the RF power knob desired energy region.

2. Tune RF first, then solenoids to get some current on the 0 deg Faraday cup.

3. Bend the beam 45 to scan the energy using Faraday cup at 45 deg exit.

4. Tune the RF power knob and repeat above steps to get the desired energy.

Tune to maximize current

1. Tune RF first, then Solenoids to get some current on the Faraday cups.

2. Use gun steerers to maximize the current on the FC.

3. Use output steerers to maximize the current on the FC.

4. Use quads to maximize current on the Faraday cup.

5. If the energy of the beam is higher than 12 MeV, electron beam can be observed. Beam size can be minimized by using OTR screen.

Bending the beam 90 deg

1. Turn on Dipoles, set them to turn same energy.

2. Bend the beam

Positron rate measurements

Target in , Target out, Sweep magnet