The Oxford University student who wrote a defiant open letter to the teenager who sexually assaulted her has told how the attack has left her living in fear.

As the 17-year-old was sentenced to a year in detention yesterday, Ione Wells described the terror she endured after the youth pounced on her as she walked home from a Tube station.

The English student, who waived her right to anonymity last month to write movingly of her ordeal in a letter published in her university newspaper, added that she had lost her confidence after the attack and would be haunted by the memories for the rest of her life.

Ione Wells, pictured, was grabbed from behind by the Somali attacker in Chalk Farm, north London

The teenage predator, pictured outside court today, who sexually assaulted Oxford University student Ione Wells. He was jailed for two years and cannot be identified for legal reasons

'The attack was the most traumatic experience I have ever endured,’ the 20-year-old said in a victim impact statement read out in court. ‘I have lost the feelings of safety and confidence and the security of my mental health – all the values built up for a lifetime and one boy has robbed me of all of it.

‘I can’t close my eyes without hearing my attacker’s footsteps behind me. He knows the area where my neighbours and I live and I am anxious that he will come back to get me.’ The teenager, who cannot be named for legal reasons, followed Miss Wells to her home in Camden, north London, and grabbed her from behind.

During the struggle, he banged her head against the ground and covered her mouth before grabbing her chest with such force it tore her bra in half.

The Keble College student was saved when neighbours heard her screams and intervened. Hours later, the attacker was arrested after being spotted on CCTV following another woman. ‘I was attacked and violently assaulted on the road I call home,’ said Miss Wells in her statement read at Highbury Corner Youth Court.

‘I can’t read the words rape, assault or attack or hear footsteps behind me without feeling anxious. Had it not been for a few neighbours, [the youth] would have left me raped, possibly impregnated with a stranger’s child, with severe if not fatal injuries.’

Ione Wells, 20, prompted an outpouring of public support when she wrote a defiant missive to her assailant, telling him he 'would not win' after the attack in Chalk Farm, north London, last month

She said the attack had made her feel ‘nauseous’ about her body, adding: ‘I feel insecure about myself.

‘I can’t look at my own body without thinking how my attacker hit me so hard that I bled.

‘My body feels tainted and violated by a stranger who thought he had the right to violate my body.’

The student, who is preparing for exams, added that her attacker has ‘robbed me of an important time in my academic career that I have worked years to get and I will never get back’.

The court heard she felt she was an ‘incredibly independent young woman’ before the assault but now suffers from panic attacks. Miss Wells received an outpouring of support following her open letter, in which she vowed not to let her attacker ruin her life.

She spoke out to help launch a campaign called #notguilty, which aims to prevent victims of sex attacks being blamed for their ordeals. District Judge Gillian Alison described the assault as serious and violent. She sentenced the youth to a two-year detention order, of which he will spend half locked up and the other half under supervision.

The judge said he was ‘only a month or so shy’ of reaching adulthood and would have faced 32 months in prison if he were over 18.

She added that the attack has had a ‘severe and potentially life-long psychological impact’ on Miss Wells. The teenager, who has been placed on the sex offenders’ register for five years, did not react as his sentence was read out.

Originally from Somalia, he lives with his family in a council flat not far from the crime scene. He was still attending college after the attack.

In defence, Vanessa James described the youth as ‘emotionally immature and not sexually mature’. She added: ‘It appears to be something that was not premeditated but something that he deeply regrets now’.

In an interview last week, Miss Wells said she was considering facing the youth in court. However, she did not appear yesterday.

She revealed that it took her only 15 minutes to write her letter of defiance, in which she wrote: ‘You, my attacker, have not proved any weakness in me, or my actions, but only demonstrated the solidarity of humanity.’