Beam Test Apr 26 2012

Coil current vs Electron Beam Energy

Coil           En                Mod HVPS Grid Set
Current 
(Amp)          (MeV)
6.50 	 	3.49960871
15.25 	 	8.04790047        
15.3                             4.12  (En Switch off)
24 	 	12.5378648        4.30  (En Switch off)
33 	 	15.6004336        4.84  (En Switch off)

Preparation

[Check List]

1. Magnets (on/off)

2. Camera: (on/off) (Sync) (shielding)

3. Flags: (In/Out)

4. Farady Cup: hocked up?

5. Blank off for camera on?

6. Gas bottle for valve full?

7. Gas bottle for flags full?

15.6 MeV Setting

Quad Scan is done here with Q1.

Energy switch changed to low energy setting. Part of the cavity is grounded.

Energy Switch	Out (High En Range)
Dipole Coil Current	33
e- Beam Energy ()	15.6004336 MeV (mapping )
Solenoid 1	A
Solenoid 2	A
Gun Hor	0 A
Gun Ver	0 A
Output Hor	0.4 A
Output Ver	0.3 A
Rep Rate	6
Gun HV	8.99(Knob Setting)
Gun Grid Voltage	10 (Knob Setting)
RF frequency	2856.291 MHz
Modulator HV Power Supply	4.84 (Knob Setting)
RF macro Pulse Length (FWHM)	300 ns
Q1 (A)	0
Q2 (A)	0
Q3 (A)	0
Q4 (A)	0
Q5 (A)	0
Q6 (A)	0
Peak Current on FC 1 (45 deg)	88.8 mAmps
Peak Current on FC 2 (45 deg)	26.4 mAmps
Scope on FC 1	200 px
Scope on FC 2	200 px
Beam Spot	200 px

Gun has been up to air for 3 times. It could be oxidation, contamination. Or it could be gun died, less likely. Roasting the gun to burn off the contamination is an idea. Chad just roasted gun for with higher current, we saw gun current increased many times. We will leave roasted for one night.

En spread and En measurement

File name in Flash drive.

File Name in Flash Drive	Dipole Coil Current (Amps)
tek00008.png	24
tek00009.png	25
tek00010.png	26
tek00011.png	27
tek00012.png	27.5
tek00013.png	28
tek00014.png	28.5
tek00015.png	29
tek00016.png	29.5
tek00017.png	30
tek00018.png	30.5
tek00019.png	31
tek00020.png	31.5
tek00021.png	32
tek00022.png	32.5
tek00023.png	32.8
tek00024.png	33
tek00025.png	33.2
tek00026.png	33.5
tek00027.png	34
tek00028.png	35
tek00029.png	36
tek00030.png	38
tek00031.png	40
tek00032.png	42
Power supply limit is 42 Amp

Assumed 10 MeV Setting

Energy set to close to 10 Region.

Energy switch changed to low energy setting. Part of the cavity is grounded.

Energy Switch	Out (High En Range)
Dipole Coil Current
e- Beam Energy ()	MeV (estimate)
Solenoid 1	5.7 A
Solenoid 2	1.8 A
Gun Hor	0 A
Gun Ver	0 A
Output Hor	-0.4 A
Output Ver	0.3 A
Rep Rate	30
Gun HV	10.0(Knob Setting)
Gun Grid Voltage	10.0 (Knob Setting)
RF frequency	2856.290 MHz
Modulator HV Power Supply	4.21 (Knob Setting)
RF macro Pulse Length (FWHM)	500 ns
Q1 (A)	0
Q2 (A)	0
Q3 (A)	0
Q4 (A)	0
Q5 (A)	0
Q6 (A)	0
Peak Current on FC 1 (45 deg)	42.8 mAmps
Peak Current on FC 2 (45 deg)	15.76 mAmps
Scope on FC 1	200 px
Scope on FC 2	200 px file name in flash drive is 10MeV_20A.png
Beam Spot	200 px

File Name in Flash Drive	Dipole Coil Current (Amps)
tek00032.png	8
tek00033.png	9
tek00034.png	10
tek00035.png	11
tek00036.png	12
tek00037.png	13
tek00038.png	14
tek00039.png	15
tek00040.png	16
tek00041.png	17
tek00042.png	18
tek00043.png	19
tek00044.png	20
tek00045.png	21
tek00046.png	22
tek00047.png	23
tek00048.png	24
tek00049.png	25
tek00050.png	17.5
tek00051.png	18.5
tek00052.png	19.5
tek00053.png	20.5
tek00054.png	21.5
tek00056.png	22.5
tek00057.png	23.5

MeV Setting Energy with Switch on, Highest Mod HVPS (5.0 nob)

Energy switch turned on.

Dipole Set to MeV.

Energy switch changed to low energy setting. Part of the cavity is grounded.

Energy Switch	Out (High En Range)
Energy with Switch	on
Dipole Coil Current	20
e- Beam Energy ()	10 MeV (estimate)
Solenoid 1	13.7 A
Solenoid 2	9.1 A
Gun Hor	0.5 A
Gun Ver	0 A
Output Hor	0.4 A
Output Ver	0.3 A
Rep Rate	30
Gun HV	10.0(Knob Setting)
Gun Grid Voltage	10.0 (Knob Setting)
RF frequency	2856.450 MHz
Modulator HV Power Supply	5.0 (Knob Setting)
RF macro Pulse Length (FWHM)	500 ns
Q1 (A)	0
Q2 (A)	0
Q3 (A)	0
Q4 (A)	0
Q5 (A)	0
Q6 (A)	0
Peak Current on FC 1 (45 deg)	42.8 mAmps
Peak Current on FC 2 (45 deg)	36.8 mAmps
Scope on FC 1	200 px
Scope on FC 2	200 px
Beam Spot	200 px

File Name in Flash Drive	Dipole Coil Current (Amps)
tek00057.png	12
tek00058.png	13
tek00059.png	14
tek00060.png	15
tek00061.png	13.5
tek00062.png	14.5
tek00063.png	15.5
tek00066.png	16
tek00067.png	16.5
tek00068.png	17
tek00069.png	18
tek00070.png	19
tek00071.png	20
tek00072.png	21
tek00073.png	22
tek00074.png	23
tek00075.png	24
tek00076.png	25
tek00077.png	26
tek00078.png	27
tek00079.png	28
tek00080.png	29
tek00081.png	30
tek00082.png	31
tek00083.png	32

Energy switch turned on.

Dipole Set to MeV.

Energy switch changed to low energy setting. Part of the cavity is grounded.

Energy Switch	Out (High En Range)
Energy with Switch	on
Dipole Coil Current	15.3
e- Beam Energy ()	10 MeV (estimate)
Solenoid 1	13.7 A
Solenoid 2	9.1 A
Gun Hor	0.5 A
Gun Ver	0 A
Output Hor	0.4 A
Output Ver	0.3 A
Rep Rate	30
Gun HV	10.0(Knob Setting)
Gun Grid Voltage	10.0 (Knob Setting)
RF frequency	2856.450 MHz
Modulator HV Power Supply	5.0 (Knob Setting)
RF macro Pulse Length (FWHM)	500 ns
Q1 (A)	0
Q2 (A)	0
Q3 (A)	0
Q4 (A)	0
Q5 (A)	0
Q6 (A)	0
Peak Current on FC 1 (45 deg)	42.8 mAmps
Peak Current on FC 2 (45 deg)	36.8 mAmps
Scope on FC 1	200 px
Scope on FC 2	200 px
Beam Spot	200 px

File Name in Flash Drive	Dipole Coil Current (Amps)
tek000.png	15.3

Quad Test

Tune HRRL

Tune to following settings, observe beam. Check if there is mis-steering by quadrupole magnet.

This tune used for quad scan at Mar 17 2011, tuned by Dr. Kim.

Solenoid 1	6.8 A
Solenoid 2	10.4 A
Gun Ver	-0.2 A
Gun Hor	+0.4 A
Output Hor	-1.4A
Output Ver	-0.5 A
Gun HV	+9.75 (Knob Setting)
Gun Grid Voltage	5.25 (Knob Setting)
RF frequency	2855.816 MHz
Modulator HV Power Supply	4.42 (Knob Setting)
RF macro Pulse Length (FWHM)	200 ns
Peak Current on FC	37.2 mAmps
Scope on FC
e- Beam Energy	14 MeV

Test mis-steering

Use OTR screen observe the beam. Turn all the quads off, except one at time. Change quad currents, see if mis-steering happens.

Quad	Is there mis-steering?	Beam images for different quad coil currents
Q1		200 px 200 px 200 px
Q2		200 px 200 px 200 px	Q3		200 px 200 px 200 px
Q4		200 px 200 px 200 px
Q5		200 px 200 px 200 px	Q6		200 px 200 px 200 px

Emittence Test (If time allows?)

Tune HRRL establish stable beam

1. Looking at the beam position on the screen and by the beam current on FC, try to align beam line. The goal is to center the beam on the screen, and maximize the FC charge as high as possible.

2. Reduced the mis-steering at the quadrupole by tuning steerers in the linac.

3. Optimize steerers, solenoids in linac to get a round electron beam shape and no steering at the quadrupole.

4. One good tune earlier for reference: [Tune HRRL]

10 MeV

Energy is set by bending the beam to dipole at specific current.

Set dipole current for 10 MeV, and bend the beam. Tune the beam energy, until we see peak current at the 45 degree Faraday cup.

Emittance measurement at 10 MeV

This is scan for 10 MeV beam. 40 mAmps peak current. Q1 is on, All other quads are off.

1) Scan from -5 Amps to 5 Amps. Increment at 0.2 Amps.

3) Name images by numbers start from 1. Then go on. Like: -5 Amp is 1, -4.8 Amp is 2, and so on til 5 Amp is named 51.

4) Scan multiple times from -5 to 5 Amps, and put them in different folders. Name folder by number, like 1, 2, 3 etc. After finishing one scan go back to -5 Amps. When going back take small steps (like 1 Amp), do not jump from 5 Amps to -5 Amps directly. After reaching back to -5, wait for few moment (like 10 s).

5) For each time, take back ground images. It should be done when RF is on and gun is off.

6) After the scan take a scope image for the current of the FC after the OTR screen. Lower the current, so the vacuum window do not heat up. This step is to check energy.