1. Gaussian TEL gun progress V. Kamerdzhiev, G. Kuznetsov, V. Shiltsev LARP Collaboration Meeting 10 Danfords on the Sound, Port Jefferson, NY, April 23-25, 2008

2. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 2 The e-gun design The electrode geometry is optimized for generating Gaussian-like transverse current density distributions (profiles) using SuperSam/UltraSam code* * M. Tiunov, INP Novosibirsk, Russia anode control electrode (CE) cathode

3. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 3 The electron gun assembled on a 6 ¾ conflat flange

4. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 4 The test bench gun solenoid main solenoid collector solenoid

5. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 5 Profile measurement technique I = const the deflector current is ramped in small steps at every step the probe current is recorded

6. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 6 Electron beam analyzer 0.2 mm holethe current probe ADCPC

7. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 7 3D current density distribution @ 8kV

8. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 8 Profiles vs U ce @ U cath = 5kV

9. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 9 Maximum ratings U cath = -10kV; U anode = U cath, Gnd; I peak max = 1.65A; @ B gun = 4kG; 5*10 -9 Torr The rise/fall time is defined by the driver circuit. Applying positive voltage to the CE in respect to the cathode will result in higher peak electron current

10. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 10 Summary The Gaussian electron gun was successfully tested on the test bench at up to 10kV What to do next –install the Gaussian e-gun in one of the TELs –since the e-p beam alignment is very critical we need to figure out the best way to achieve/maintain optimum e-p alignment the Digital Tune Monitor seems to be the best candidate capable of detecting the tune spread change (work in progress)

11. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 11 Backup slides proposed hollow electron beam for LHC collimation system –e-gun simulations are performed using UltraSam code –simulations done by L. Vorobiev –mechanical considerations by G. Kuznetsov goals –keep the transverse electron energy low –extract as much current as possible –simulate e-beam compression in solenoidal magnetic field

12. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 12 Hollow e-beam for LHC collimation system cathode near cathode electrode control electrode anode cylindrical symmetry current density distribution (profile)

13. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 13 Example 2

14. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 14 Example 3

15. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 15 Simulated profile comparison the proton beam passes through the zero e-current area

16. V. Kamerdzhiev for BBC teamGaussian TEL gun progress 16 Summary the “hollow” gun can be simulated with the tools we have (Super/Ultra SAM) –first look shows promising results mechanical design looks doable the infrastructure for testing the gun (once it’s been built) is available we plan to continue the development and demonstrate the detailed design