Beam Test Apr 24 2012

Getting Ready Punchlist

1) Get matlab ready for emittance measurement. (Not done due to Matlab licence issue)

(Done) 2) Install control box. 
(Done) 3) Clean up imaging system.
(Done) 4) Determine dipole current setting.

Test List

Energy Test

1. Chad tunes HRRL

4.11

RF: 2857.351

MOD HVPS	RF	FC1
4.11 (nob)	2857.351	34.2 mA

Test beam stability at different energies

Start from 2 MeV go up energy.

Assuming magnet polarity swith "up" as positive and "down" as negative.

e- Beam Energy (estimate)	16 MeV
Solenoid 1	A
Solenoid 2	A
Gun Ver	-0.2 A
Gun Hor	0 A
Output Hor	-0.3 A
Output Ver	-1.2 A
Gun HV	(Knob Setting)
Gun Grid Voltage	(Knob Setting)
RF frequency	2856.382 MHz
Modulator HV Power Supply	4.98 (Knob Setting)
RF macro Pulse Length (FWHM)	300 ns
Q1 (A)	0
Q2 (A)	0.6
Q3 (A)	0
Q4 (A)	+10
Q5 (A)	-7
Q6 (A)	-5
Peak Current on FC	135 mAmps
Scope on FC	200 px
Beam Spot	200 px

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.

15 MeV

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

Set dipole current for 15 MeV, and bend the beam. Tune the beam energy, until we see peak current at the 45 degree Faraday cup.

3 MeV

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

Set dipole current for 15 MeV, and bend the beam. Tune the beam energy, until we see peak current at the 45 degree Faraday cup.

7 MeV

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

Set dipole current for 7 MeV, and bend the beam. Tune the beam energy, until we see peak current at the 45 degree Faraday cup.