Mar-01-2000

1. RFP workshop

2. Modify HV controller's 'reset' circuit

Mar-02-2000

Discuss with Jim Adney about the accelerator

Mar-07-2000

Check the gradient resistors on the accelerator's column

Mar-09-2000

Test different gradient voltage on the accelerator's column. Doesn't seem get benifit.

Mar-12-2000

Calibration of the primary sweep plates

1. Use toroidal 10kV (T10) plates to calibrate toroidal 4kV (T4) plates

2. Use shutter plate to calibrate T4 plates

3. Use shutter palte to calibrate T10 plates

4. Use poloidal 20kV (P20) plates to calibrate poloidal 4kV (P4) plates

5. Calibration of the radial sweep plates by using primary beam detectors

Mar-14-2000

Take accelerator's gun apart

1. Correct the extractor-tube's angle to <0.1 deg around the axis (previously ~ 0.5 deg)

2. Digital pictured the parts. See Pierce structure of the accelerator.

3. Put another cooling fan on the primary turbo.

Mar-15-2000

Modify the Pierce structure

1. Pierce hole is enlarged to 4.85mm (just little larger than the source cup)

2. Extractor hole is enlarged a little bit to ~ 3.3mm

3. Make new two bundles of co-ax to the control rack. Two bundles to the analyzer patch panel.

Mar-16-2000

Put Pierce parts together, don't put the washer inside the extractor tube

Mar-21-2000

Test of the new 3-turn ion source

1. Put #2

2. Start to emit at ~ 3A filament current

3. FWHM ~ 10mm. Clear to see 3 peaks in the profile

4. At If ~ 4.5A, notice high offset at BPM, I-Pierce jump to 265uA. Charge exchange causes no control over the extractor.

Mar-23-2000

Test of the new ion source

1. Pierce-Extractor space ~ 10.2mm

2. Pierce - 300MOhm, Ectractor -200MOhm. at Wb = 50keV, notice a lot of charge exchange between P-E

3. Connect the extractor to 100MOhm, no great help

Mar-24-2000

Change the P-E space to ~ 14.01mm, and repeat the test

1. E-100MOhm. Lose control of the extractor at higher filament current

P	E	Acc	I-filament	BPM	Shutter (no bias)	Size at BPM
33.6kV	29.1kV	17.4kV	6.1A	5uA	42uA	10mm
45.6kV	38.4kV	21.6kV	5.2A		45uA
45.6kV	38.8kV	23.4kV	5.8A		60uA

2. Try connect 50MOhm to the extractor stack. The Pierce Glassman power supply is blown up.

3. The Glassman latches into C.C mode when turn it on.

4. Change the extractor electrode to the one with hole size = 6.2mm. At this time the P-E spacing is 13.21mm

Mar-27-2000

Check Glassman power supply

Mar-29-2000

1. The Glassman power supply is repaired. The output power transistors 2N6251 are bad. Change to use BUF420M

2. Test of the H.V up to 80kV ok.

Mar-30-2000

Test of the ion source

1. Dis-connect the resistor on the Pierce stack. The extractor stack still connects to a 100MOhm resistor.

2. Wb = 45keV, E = 40kV, A = 31.6kV, If = 6A, I_shutter = 40-80uA w/o bias.

3. Lost control above E = 40kV

4. Change to a new ion source #3, start emitting at 4.0A filament current

5. P-E space is changed to ~ 9.4mm, extractor hole size still 6.2mm

6. If = 4.8A, I_shutter = 10uA; If = 5A, I_shutter=13uA (w/o bias)

Mar-31-2000

Test of the ion source and the Pierce structure

1. It seems that the ion source works better than last day

2. Lose control of the extractor at I_shutter above 60uA (w/o bias), and extraction voltage ~ 5-7kV.

see progress report as of April-5-2000.

3. Change back to the original Pierce electrode with the hole size ~ 2.45mm, but with a centering jig now. The hole size of the extractor is still 6.2mm, keep the same #3 ion source

4. Wb = 45keV, I_shutter ~ 30-40uA (w/o bias), size at BPM ~ 10mm

5. No obvious change of I_shutter when the filament current is bring up to 8A