JLC/NLC Charge, Jitter, and Emittance

Emittance budgets for Stage 1 and Stage 2

Jitter budgets for Stage 1 and Stage

Charge Requirements for the JLC / NLC (4/15/99)
	500 GeV or 1 TeV case C			Maximum Charge
	e- [10¹⁰]	e+ [10¹⁰]	loss	e- [10¹⁰]	e+ [10¹⁰]	loss
From e+ drive beam e- gun		2.4			2.4
			30% (A)			30% (A)
e- at 80 MeV		1.65			1.65
			10% (B)			10% (B)
e- at 6 GeV before e+ target		1.5			1.5
			2.1 yield (C)			2.1 yield (C)
e+ at 250 MeV		3.2			3.2
			60% (D)			50% (E)
e+ at 2 GeV		1.25			1.6
e+ at PPDR entrance		1.25			1.6
			5% (F)			5% (F)
e+ at PPDR exit		1.18			1.5
From e- polarized gun	1.9			2.4
			30% (A)			30%
Pol. e- at 80 MeV	1.3			1.65
			10% (B)			10%
Pol. e- at 2 GeV	1.18			1.5
MDR entrance	1.18	1.18		1.5	1.5
			5% (F)			5% (F)
MDR exit	1.12	1.12		1.42	1.42
			1% (G)			1% (G)
Injector Exit (10 GeV)	1.1	1.1		1.41	1.41

Main linac exit	1.1	1.1		1.41	1.41
			0.10% (H)			0.10% (H)
Collimation exit	1.1	1.1		1.41	1.41
At IP	1.1	1.1		1.41	1.41

Notes:

30% loss from gun includes effect of charge limiting aperture

10% loss in linac is based on high charge SLC operation

Yield of 2.1 at 250 MeV is based on EGS calculations

60% loss is based on SLC operation where the yield is decreased by 2.5 from the expected yield—we have attempted to design away the apertures that limit the system but maintain the loss for overhead

50% loss is based on expected improvements in performance needed to attain the higher charge while still providing a substantial overhead

5% injection losses are comparable to best SLC performance but higher losses will cause unacceptable radiation levels so we must design to minimize the losses here. Note: 5% losses in the damping rings corresponds to about 3kW of beam loss which is a very large radiation load and is likely too much.

1% loss at pre-linac collimation system

0.1% loss at main linac collimation system

Created: 04/15/99 by Tor Raubenheimer

Modified: 06/13/01 by Tor Raubenheimer