# Presentation: 676150

## Machine Parameters

| Parameter [units] | Tune-up beam | "low" charge | high current | high charge |
| --- | --- | --- | --- | --- |
| Kin. injection energy [MeV] | 2.0 – 3.0 | 2.0-3.0 | 2.0 | 2.0-3.0 |
| Maximum beam energy [MeV] | 16 – 20 | 16-20 | 16-20 | 16-20 |
| Bunching freq [MHz] | 10-6 - 9.383 | 9.383 | 351.88 / 703.76 | 9.383 |
| Bunch charge [nC] | 0.1 - 1.4 | 1.4 | 1.4 / 0.7 | 5 |
| Average beam current [mA] | 10-7 – 14 | 14 | 500 | 50 |
| Bunch parameters at 2.5 MeV |  |  |  |  |
| x/y, normalized, [mm-mrad] | 1/1 – 2/2 | 2/2 | 2/2 | 6/6 |
| Bunch length, full/rms, [ps] | ~60-120/20-40 | ~60-120/20-40 | ~60-120/20-40 | ~80-150/30-55 |
| Energy spread, full/rms, dE/E | 0.03-0.08/
0.005-0.01 | 0.03-0.08/
0.005-0.01 | 0.03-0.08/
0.005-0.01 | 0.08-0.01 |
| Bunch parameters at 20 MeV |  |  |  |  |
| x/y, normalized, [mm-mrad] | 1/1-2/2 | 2/2 | 2/2 | 6/6 |
| Bunch length, full/rms, [ps] | ~60/20 - 120/40 | ~120/40 | ~120/40 | ~150/55 |
| Energy spread, full/rms, dE/E | 0.06/0.01 | 0.06/0.01 | 0.06/0.01 | 0.08/0.015 |

## AP requirements (High Energy Ring)

| Parameter | Expected Value / Range | Accuracy | Resolution | Comments |
| --- | --- | --- | --- | --- |
| Beam Loss (localized) | 50 nA (trip level) /
0-2500 nA (range) | 20% | 0.5 nA | BLM trip level is 50 nA. Factor of 50 down required for smooth transition during laser frequency increase. Laser specs are not completely clear at this point. |
| Beam Position |  |  |  |  |
| Transverse, 
1st-time tuning | Full aperture, Bunch rep. rate 1 Hz | 500 μm | 50 μm | Flags could be used to bring the beam around. |
| Transverse, Regular Operations/Tuning | Aperture: ±1.5 cm,
≥10 Hz, two beams | 100 μm | 20 μm | Ideally, position of accel./decel. beams simultaneously. Ability to operate with bunch trains. Refresh rate not lower than 1 Hz. Ability to improve accy. by averaging. |
| accel./decel. phase | ±90° / 360° | 1° | 0.25° |  |
| Beam Profile |  |  |  |  |
| Beam emittance | 2 – 10 μm, norm | 30% | 0.1 μm, norm | ε=2 μm is nominal. Quad/Sol. scan. See next line.  |
| Transverse Beam Profile | Size (rms): 0.1-5.0 mm. (Aprt. ±1.0 cm) | 10% (LP)  | 5 μm (LP)  | High resolution is required for quad scan and beam matching in the low power (LP) mode. In the high power regime (HP), lower accy./res. can be sufficient. |
| Beam Halo Profile |  | 30% |  1 ppm of max. density | A set of scanner wires with a BLM? |
| Longitudinal profile | 50-150 psec | 10 psec | 2 psec | Required at LP and HP.  |
| Energy spread (dE/E) | 1% (rms) | 1e-3 | 2e-4 | Required at LP and HP. |
| Current/Charge per bunch |  |  |  |  |
| Current (Ops.) | 0 – 500 mA | 1% | 0.1% at I=500 mA
/ 0.25 μA at I=0 mA | Lower range needed for tuning (see next page) |
| Tot. Current Loss | < 1 μA (expected) | 1% | 0.25 μA | Requires nulling feedback, nulling cur. in both DCCTs |
| Bunch charge | 0.1 – 5 nC, 
1 Hz – 10 MHz | 5% | 0.1% (at 5 nC) | Resolution of 0.1% is desirable for RHIIC II R&D. 1% will be sufficient for ERL. |
| Other |  |  |  |  |
| HOM power |  |  |  |  |
| BTF |  |  |  | Impedance measurements? Kicker in the injector? |
| M56 (over 2 arcs) | ±20 cm | 10% | 0.5 cm | Longitudinal BTF. Non-linear terms too.  |

## AP requirements (Low Energy Injection Transport / Dump)

| Parameter | Expected Value/Range | Accuracy | Resolution | Comments |
| --- | --- | --- | --- | --- |
| Beam Loss (localized) | 0.5 μA (trip level) /
0 - 25 μA (range) | 20% | 5 nA | BLM trip level is 0.5 μA. Factor of 50 down required for smooth transition during laser frequency increase.  |
| Beam Position |  |  |  |  |
| Transverse, 
1st-time tuning | Full aperture, Bunch rep. rate 1 Hz | 500 μm | 50 μm | Flags could be used to bring the beam through |
| Transverse, Regular tuning and Operations | Aperture: ±1.5 cm,
 ≥10 Hz | 200 μm | 50 μm | Ability to operate with bunch trains. Refresh rate not lower than 1 Hz. |
| accel. phase |  | 1° | 0.25° |  |
| Beam Profile |  |  |  |  |
| Beam emittance | 2 – 10 μm, norm | 30% | 0.1 μm, norm | Pepper pot in the injection line. Projected emittance will be larger than the slice emittance. |
| Transverse Beam Profile | Size (rms): 2.0-5.0 mm. | 5% (LP) | 20 μm (LP)  | Required in the low power (LP) only. In the high power regime (HP), position will be sufficient. |
| Beam Halo, measure/remove | Full apperture,  | 20% | 1 nA, assuming 
2π scraper | A factor of 10 better resolution is required for RHIC II R&D. |
| Current/Charge per bunch |  |  |  |  |
| Current (Tuning) | 0 - 1 μA  | 5% | 0.5 nA | Ring BLM tuning will require damping 50 nA locally.   |
| Current (Ops.) | 0 – 500 mA | 1% | 0.1% at I=500 mA
/ 0.25 μA at I=0 mA |  |
| Bunch charge | 0.1 – 5 nC, 1 Hz -10  MHz | 5% | 0.1% (at 5 nC) | Resolution of 0.1% is desirable for RHIIC II R&D. 1% will be sufficient for ERL. |
| Ghost bunches | ~10 nA @ 10 MHz | 20% | 1 nA @ 10 MHz | Must be measured separately from main bunches. |
| Other |  |  |  |  |
| Gun HOM excitation |  |  |  | Beam position at the chicane BPMs as afunction of beam current/ bunch rep. rate? |
| BTF |  |  |  | Impedance measurements. Kicker in the injector? |