Hours on the Linac 7835 Power Amplifiers

Last data update: Tue Aug 12 18:30:13 CDT 2008

Station Tube S/N Gradient Filament A Hours Days Fraction of
median* life
1 A27R6 1 6525 25092 1045 1.59
2 BV3 1 6722 11447 476 1.06
3 BV15 1 6795 8909 371 0.82
4 BA1 0.98 6786 5301 220 0.49
5 BV17 1 6709 6618 275 0.61
7 BA3 -0.01 187 2354 98 0.21

*Median lifetime for tubes is about 10750 hours (15750 for tank 1). This is 447 days (656 for tank 1).

Spare 7835 Inventory

  • N27R8, 62 hours
  • AZ4R1, 348 hours
  • A20R8, 219 hours
  • BK3R1, 870 hours
  • A1R9, 388 hours
  • C2R7, 0 hours
  • A30R7, 0 hours
  • Y2R8, 0 hours
  • BV12, 335 hours
  • BV13, 0 hours
  • BV15, 0 hours
  • BV17, 0 hours
  • BA1, 0 hours
  • BA2, 700 hours
  • BA5, 0 hours
  • BA6, 0 hours
  • BA7, 0 hours

    • 7835 Delivery Schedule

    Regular Deliveries
    TubeDeliveryStatusOwner
    BK1 Unknown Returned to Burle 12/05 FNAL
    New 12/06 FNAL
    		Bulk Order of New Tubes (Feb, 2005)
    Order completed on April 4, 2006
    All delivery dates are estimates
    Last modified: Tue Sep 20 09:00:55 CDT 2006

    The following tubes are getter-less:

    Klystron Hours

    ModuleMnf*S/NHoursDaysYearsInternal
    Vacuum
    uA
    0 V L122 122052 5085 13.9 0.35
    V V L113 126114 5254 14.3 0.00
    1 L 005R1 37026 1542 4.2 0.01
    2 L 004 125124 5213 14.2 0.00
    3 L 006 109509 4562 12.4 0.07
    4 L 016 39856 1660 4.5 0.04
    5 L 007 128327 5346 14.6 0.01
    6 L 013R1 65798 2741 7.5 0.06
    7 L 015 110477 4603 12.6 0.47
    D V A21 108308 4512 12.3 0.00

    *Mnf = "Manufacturer", V is Varian VKP-7955 and L is L3 (Litton) L-5859

    Spare Klystron Inventory

  • V_K107, 0 hours
  • V_L026Z, 8086 hours
  • L_0003, 2194 hours
  • L_0010, 5621 hours
  • L_0011, 37163 hours
  • L_0017, 0 hours
  • L_0018, 0 hours
  • L_0019, 0 hours

    • The last two klystron to fail were in KRF4, S/N 0009, at 83278 hours on November 14, 2003 and in KRF1, S/N 0002R1, at 29345 hours, on December 23, 2003. These klystrons failed due to severe vacuum problems. We have replaced two other klystrons since 1993 (at KRF1 and at KRF6).

    Of all the tube that have failed, 5 have failed offline with essentially no hours on them (due to vacuum problems). Of the failed tubes with significant hours, they had 83278 (S/N 0009), 64000, 43800, 37000, 29345 (S/N 0002R1) and 27000 hours when they failed..

    The delivery schedule for the klystrons being rebuilt is as follows:

    TubeDeliveryComments
    0014 September 2005
    0008 October 2005
    Schedule Last modified: Fri Aug 26 13:48:44 CDT 2005

    Last data update: Tue Aug 12 18:30:13 CDT 2008